High performance fiber-reinforced composite materials and articles

Abstract

Generally described herein are fiber-reinforced composite materials and related articles and methods.

Description

[0001] HIGH PERFORMANCE FIBER-REINFORCED COMPOSITE MATERIALS AND ARTICLES

[0002] RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 729,933, filed December 9, 2024, and entitled “HIGH PERFORMANCE FIBER-REINFORCED COMPOSITE MATERIALS AND ARTICLES,” which is incorporated herein by reference in its entirety for all purposes.

[0004] TECHNICAL FIELD

[0005] Fiber-reinforced composite materials and related articles and methods are generally described.

[0006] BACKGROUND

[0007] Conventional thermoset resins such as epoxies, polyesters, and vinyl esters require elevated temperatures during curing and long curing cycles. Conventional ultraviolet (UV)- curable resins cure rapidly but often suffer from drawbacks such as limited thickness due to limited cure depth, and inferior mechanical properties, including lower heat resistance. In addition, UV-curable resins exhibit limited compatibility with reinforcement materials including but not limited to fibers or fillers. Accordingly, there remains a need for improved polymer resins and related fiber-reinforced composite materials.

[0008] SUMMARY

[0009] Generally described herein are fiber-reinforced composite materials, polymer resins, and related articles and methods. In certain embodiments, the polymer resin systems described herein advantageously address limitations associated with conventional thermal-curing and UV- curing technologies. In some embodiments, for example, a polymer resin described herein is configured to cure via exposure to one or both of actinic radiation and heat, including dualcuring compatibility, thereby enabling enhanced processing flexibility and expanded material compatibility. In some embodiments, the polymer resin is impregnated into a plurality of fibers and cured and / or post-processed to provide a fiber-reinforced composite, wherein the curing and / or post-processing mechanism may be selectively tuned based on the components of the polymer resin and / or the type of fibers employed. In some embodiments, the fiber-reinforced composites produced via the methods described herein have improved thermomechanical

[0010] #14695765vl properties as compared to composites produced from conventional thermoset and / or UV-curable resins. The subject matter of the present disclosure involves, in some cases, interrelated products, alternative solutions to a particular problem, and / or a plurality of different uses of one or more systems and / or articles.

[0011] In some embodiments, a fiber-reinforced composite is described, the fiber-reinforced composite comprising a plurality of fibers and a poly(meth)acrylimide impregnated within the plurality of fibers.

[0012] In some embodiments, a method is described, the method comprising: impregnating a polymer resin into a plurality of fibers; curing the polymer resin to form a precursor polymer; and imidizing the precursor polymer to form a poly(meth)acrylimide.

[0013] In some embodiments, a method comprises: impregnating a polymer resin into a plurality of fibers, wherein the polymer resin comprises a near-infrared (NIR) dye; and curing the polymer resin by irradiating the polymer resin with NIR electromagnetic radiation to form a precursor polymer to a poly(meth)acrylimide, an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, a bismaleimide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylenesulfide, a polyether ketone, a polyether imide, a polystyrene, a vinyl ether, a lactone, a blend of two or more of the foregoing, and / or a copolymer of two or more of the foregoing.

[0014] In some embodiments, a method comprises: providing a fiber-reinforced composite comprising a precursor polymer to a poly(meth)acrylimide, a photothermal agent, and a plurality of fibers; and imidizing the precursor polymer by irradiating the fiber-reinforced composite with NIR and / or IR electromagnetic radiation.

[0015] Other advantages and novel features set forth in the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control. If two or more documents incorporated by reference include conflicting and / or inconsistent disclosure with respect to each other, then the document having the later effective date shall control.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Non-limiting embodiments will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the

[0018] #14695765vl figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment shown where illustration is not necessary to allow those of ordinary skill in the art to understand the disclosure. In the figures:

[0019] FIG. 1A shows, according to certain embodiments, a schematic diagram of an article comprising a polymer resin impregnated within a plurality of fibers.

[0020] FIG. IB shows, according to certain embodiments, a cross-sectional schematic diagram of article shown in FIG. 1A.

[0021] FIG. 1C shows, according to certain embodiments, a cross-sectional schematic diagram of an article comprising a plurality of layers.

[0022] FIG. 2 A shows, according to certain embodiments, a schematic diagram of a fiber- reinforced composite.

[0023] FIG. 2B shows, according to certain embodiments, a cross-sectional schematic diagram of the fiber-reinforced composite shown in FIG. 2A.

[0024] FIG. 2C shows, according to certain embodiments, a cross-sectional schematic diagram of a fiber-reinforced composite comprising a plurality of layers.

[0025] FIG. 3 shows, according to certain embodiments, a photograph of a glass fiber impregnated cloth.

[0026] FIG. 4 shows, according to certain embodiments, a photograph of the results of an ASTM D3359 cross-hatch test on adhesion of a poly(meth)acrylimide coating on a glass plate substrate.

[0027] FIG. 5 shows, according to certain embodiments, a photograph of a UV-cured poly(meth)acrylimide glass fiber composite.

[0028] FIG. 6 shows, according to certain embodiments, a photograph of a UV-cured poly(meth)acrylimide precursor polymer glass fiber composite.

[0029] FIG. 7 shows, according to certain embodiments, a photograph of a thermally cured carbon fiber poly(meth)acrylimide composite.

[0030] FIG. 8 shows, according to certain embodiments, the viscosity of a poly(meth)acrylimide (PMI) resin compared to various other resins.

[0031] FIG. 9 shows, according to certain embodiments, the glass transition temperature of a PMI composite compared to composite systems with other resins.

[0032] FIG. 10 shows, according to certain embodiments, the tensile strength of a PMI composite compared to composite systems with other resins.

[0033] #14695765vl FIG. 11 shows, according to certain embodiments, the elongation at break of a PMI composite compared to composite systems with other resins.

[0034] FIG. 12 shows, according to certain embodiments, the tensile modulus of a PMI composite compared to composite systems with other resins.

[0035] FIG. 13 shows, according to certain embodiments, the tensile strength of E-glass fiber, carbon fiber, and S-glass fiber composite systems.

[0036] FIG. 14 shows, according to certain embodiments, the elongation at break of E-glass fiber, carbon fiber, and S-glass fiber composite systems.

[0037] FIG. 15 shows, according to certain embodiments, the tensile modulus of of E-glass fiber, carbon fiber, and S-glass fiber composite systems.

[0038] FIG. 16 shows, according to certain embodiments, the interlaminar short-bream shear strength of E-glass fiber, carbon fiber, and S-glass fiber composite systems.

[0039] FIG. 17 shows, according to certain embodiments, the storage modulus (E’) and tan delta of a E-glass fiber and S-glass fiber composite systems.

[0040] FIG. 18 shows, according to certain embodiments, the photothermal effect of a carbon fiber composite, a glass fiber composite, and a glass fiber composite impregnated with resin with 0.5 wt.% NIR active dye. upon exposure to NIR radiation (810nm, 1.2 W / cm2)

[0041] DETAILED DESCRIPTION

[0042] Fiber-reinforced composite materials and related articles and methods are generally described. In certain embodiments, a method of fabricating a fiber-reinforced composite material comprises impregnating (e.g., infusing) a polymer resin into a plurality of fibers and curing the polymer resin. In some embodiments, the polymer resin comprises a precursor polymer, such as a precursor to a poly(meth)acrylimide. In certain embodiments, the polymer resin has a viscosity that at least partially enables the polymer resin to impregnate the plurality of fibers via any of a variety of suitable processing techniques. In some embodiments, the viscosity of the polymer resin may advantageously be tuned for a particular processing technique such as, but not limited to, resin transfer molding, vacuum assisted resin transfer molding, infusion, wet lay-up, filament winding, pultrusion, and the like.

[0043] In certain embodiments, the polymer resin is cured via thermal treatment, exposure to actinic radiation (e.g., electromagnetic radiation), and / or combinations thereof. In some embodiments, curing the polymer resin comprising the precursor to the poly(meth)acrylimide provides a precursor polymer that may be treated via a post-processing step to produce the

[0044] #14695765vl poly(meth)acrylimide. In some embodiments, the post-processing step comprises exposing the precursor polymer to one or more physical stimuli. In certain embodiments, for example, the post-processing step comprises thermal treatment, exposure to actinic radiation (e.g., electromagnetic radiation), and / or combinations thereof, which may occur concurrently to and / or after the curing step. The post-processing step may, in certain embodiments, comprise an imidization reaction of the precursor to the poly(meth)acrylimide to produce the poly(meth)acrylimide.

[0045] According to some embodiments, curing the polymer resin (and / or imidizing the precursor polymer) comprises initiating a photochemical reaction (e.g., via activation of a photoinitiator) and / or a thermal reaction (e.g., via activation of a thermal initiator). In some embodiments, for example, curing the polymer resin (and / or imidizing the precursor polymer) comprises exposing the polymer resin to actinic radiation comprising UV and / or infrared (IR) (e.g., near-infrared IR) electromagnetic radiation to initiate a photochemical reaction (e.g., via activation of a photoinitiator). In certain embodiments, curing the polymer resin (and / or imidizing the precursor polymer) comprises exposing the polymer resin to heat to initiate a thermal reaction (e.g., via activation of a thermal initiator). In some embodiments, curing the polymer resin (and / or imidizing the precursor polymer) comprises exposing the polymer resin to: (i) actinic radiation comprising UV and / or IR (e.g., NIR) electromagnetic radiation to initiate a photochemical reaction (e.g., via activation of a photoinitiator); and (ii) heat to initiate a thermal reaction (e.g., via activation of a thermal initiator). In some embodiments, the polymer resin comprises a near-infrared (NIR) dye to promote curing (e.g., polymerization). In some embodiments, the NIR dye acts as a component of a photoredox system (e.g., as a sensitizer) in conjunction with a salt initiator and an optional reducing agent. For example, in some embodiments, the NIR dye is configured to absorb NIR electromagnetic radiation and activate the salt initiator which initiates polymerization of the polymer resin. In some embodiments, the polymer resin comprising the NIR dye is exposed to: (i) UV and IR (e.g., NIR) electromagnetic radiation to initiate a photochemical reaction (e.g., via activation of a salt initiator); and / or (ii) heat to initiate a thermal reaction (e.g., via activation of a thermal initiator).

[0046] In certain embodiments, curing the polymer resin (and / or imidizing the precursor polymer) comprises initiating a photochemical reaction and / or a thermal reaction via a photothermal effect. In some embodiments, for example, the plurality of fibers comprises a material (e.g. carbon) configured to absorb electromagnetic radiation (e.g., IR electromagnetic

[0047] #14695765vl radiation, such as NIR electromagnetic radiation) and produce a photothermal effect, which may activate a photoinitiator and / or a thermal initiator to initiate polymerization of the polymer resin.

[0048] In certain embodiments, a fiber-reinforced composite is produced via the methods described herein. In some embodiments, the fiber-reinforced composite comprises a plurality of fibers and a polymer (e.g., a poly(meth)acrylimide) impregnated (e.g., infused) within the plurality of fibers. According to some embodiments, the impregnated and fully cured, solid polymer in combination with the plurality of fibers provides a composite material having desirable thermal and / or mechanical properties. In some embodiments, for example, the fiber- reinforced composite has an increased glass transition temperature (Tg) and / or improved tensile strength, elastic (e.g., tensile) modulus, and / or elongation at break as compared to conventional composite materials such as those comprising thermoset resins (e.g., curable via heat treatment) or UV-curable resins (e.g., curable via exposure to UV electromagnetic radiation).

[0049] In certain embodiments, a method comprises impregnating a polymer resin into a plurality of fibers. FIG. 1A shows, according to certain embodiments, a schematic diagram of article 101a comprising polymer resin 111 impregnated within a plurality of fibers. FIG. IB shows, according to certain embodiments, a cross-sectional schematic diagram of article 101a shown in FIG. 1A, wherein the cross-section is taken along lines IB shown in FIG. 1A. FIG. IB further shows the plurality of fibers with reference sign 110.

[0050] According to certain embodiments, the polymer resin (e.g., polymer resin 111) comprises a polymerizable mixture (e.g., a reaction mixture). In some embodiments, the polymer resin comprises a monomer, a co-monomer, and / or an oligomer. In some embodiments, the monomer, co-monomer, and / or oligomer is capable of homopolymerizing and / or copolymerizing and being incorporated into a growing polymer chain. In certain embodiments, the monomer, co-monomer, and / or oligomer is polymerized (e.g., cured) to generate a precursor polymer or a polymer. Suitable monomers, co-monomers, and / or oligomers are described herein in greater detail.

[0051] In some embodiments, the polymer resin (e.g., polymer resin 111) comprises a plurality of monomer molecules. In some embodiments, the plurality of monomer molecules comprises a plurality of monomer molecules each having the same chemical structure. In some embodiments, the plurality of monomer molecules comprises a plurality of monomer molecules each having the same chemical structure such that polymerizing the plurality of monomer molecules generates a homopolymer. In some embodiments, the plurality of monomer molecules comprises a plurality of monomer molecules having one or more chemical structures.

[0052] #14695765vl - 1 -

[0053] In some embodiments, the plurality of monomer molecules comprises a plurality of monomer molecules having one or more chemical structures such that polymerizing the plurality of monomer molecules generates a copolymer. In some embodiments, the polymerizable mixtures may comprise at least one, or two or more, monomers, for example (meth)acrylic acid and (meth)acrylamide, optionally at least one polymerization initiator, and optionally a blowing agent for optional production of foam materials. These compositions can be polymerized to generate precursor polymers, which upon treatment may result in poly(meth)acrylimide materials, via a cyclization reaction, herein termed imidization. In some embodiments, the polymer resin (e.g., polymer resin 111) comprises a (meth)acrylamide. The polymer resin comprising the (meth) acrylamide may, in some embodiments, be polymerized to generate a precursor polymer, which upon treatment may result in a poly(meth)acrylimide material, via a cyclization reaction (e.g., imidization), as described herein in greater detail.

[0054] Polymers and oligomers can comprise a plurality of repeat units. In some embodiments, a polymer comprises eleven or more repeat units. In some embodiments, an oligomer comprises two to ten repeat units. In some embodiments, a polymer is a homopolymer. In some embodiments, a polymer is a copolymer. In some embodiments, a polymer comprises a weight average molecular weight of at least 1,000 g / mol. In some embodiments, a polymer comprises a molecular weight of at least 2,000 g / mol. In some embodiments, a polymer comprises a molecular weight of at least 5,000 g / mol. In some embodiments, a polymer comprises a molecular weight of at least 10,000 g / mol. In some embodiments, a polymer comprises a molecular weight of at least 20,000 g / mol. In some embodiments, a polymer comprises a molecular weight of 1,000 g / mol to 5 x 106g / mol. In some embodiments, a polymer comprises a weight average molecular weight of 2,000 g / mol to 5 x 106g / mol. In some embodiments, a polymer comprises a molecular weight of 5,000 g / mol to 5 x 106g / mol. In some embodiments, a polymer comprises a molecular weight of 10,000 g / mol to 5 x 106g / mol. In some embodiments, a polymer comprises a molecular weight of 20,000 g / mol to 5 x 106g / mol. The weight average molecular weight of a polymer can be determined via gel permeation chromatography.

[0055] In some embodiments, a monomer or co-monomer is a molecule capable of homopolymerizing and / or copolymerizing by radical addition and being incorporated into a growing polymer chain. In some embodiments, a monomer or co-monomer provided herein is optionally substituted. Such comonomers may be, but not restricted to, acrylic acid or methacrylic acid, esters of acrylic or methacrylic acid, N-substituted (meth)acrylamides, vinyl

[0056] #14695765vl ethers, styrenes, acrylamides, maleimides, vinyl esters, vinylpyrrolidone, vinylic cyclic structures such as, but not limited to, vinyl acetal, vinyl ethers, spiro-ortho-carbonates, spiro- ortho-esters, vinyl sulfones, allilyc sulfides, vinyl oxirane, ketene acetals, and thionolactones.

[0057] In some embodiments, an acrylate monomer comprises a vinylic acid or ester moiety. In some embodiments, an acrylate monomer is optionally substituted. In some embodiments, an acrylate monomer is an unsubstituted acrylate monomer. In some embodiments, an acrylate monomer is a substituted acrylate monomer. In some embodiments, an acrylate monomer is an acrylic ester monomer optionally substituted at the ester position, a methacrylic ester monomer optionally substituted at the ester position, an acrylic acid monomer, a methacrylic acid monomer, a salt of an acrylic acid monomer, or a salt of a methacrylic acid monomer. As used herein, the term (meth) acrylate comprehends both acrylate monomers that are not substituted at the vinylic position to form methacrylates and methacrylate monomers. In other words, (meth)acrylates can include unsubstituted acrylates, acrylates substituted at the vinylic position to form methacrylates, acrylates that are substituted at the ester position but not substituted at the vinylic position, and acrylates that are substituted at both the vinylic position and ester position.

[0058] Examples of acrylate monomers include, but are not limited to, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2- hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, 2- hydroxyethyl acrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isobomyl methacrylate, isobornyl acrylate, glycidyl acrylate, glycidyl methacrylate, dicyclopentanyl acrylate, and dicyclopentanyl metahcrylate.

[0059] As used herein, the term “acrylic-containing group” or “methacrylate-containing group” refers to a compound that has a polymerizable acrylate or methacrylate group.

[0060] In some embodiments, an acrylamide monomer comprises a vinylic amide moiety. In some embodiments, an acrylamide monomer is optionally substituted. In some embodiments, an acrylamide monomer is an unsubstituted acrylamide monomer. In some embodiments, an acrylamide monomer is a substituted acrylamide monomer. In some embodiments, an acrylamide monomer is an acrylamide monomer optionally substituted at the vinylic position or an acrylamide monomer optionally substituted at the amide nitrogen atom. As used herein, the term (meth)acrylamide comprehends both acrylamide monomers that are not substituted at the vinylic position to form methacrylamides and methacrylamide monomers. In other words, (meth)acrylamides can include unsubstituted acrylamides, acrylamides substituted at the vinylic

[0061] #14695765vl position to form methacrylamides, acrylamides that are substituted at the amide nitrogen atom but not substituted at the vinylic position, and acrylamides that are substituted at both the vinylic position and the amide nitrogen atom. Examples of acrylamide monomers include, but are not limited to, acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N- butylacrylamide, N-[3-(dimethylamino)propyl]acrylamide, 4-acryloylmorpholine, N-[2- (dimethylamino)ethyl]acrylamide, N-[2-(diethylamino)ethyl]acrylamide, diacetone acrylamide, N-(2-hydroxyethyl)acrylamide, N-isopropylacrylamide, N-propylacrylamide, N-(2-amino-2- oxoethyl)acrylamide, N-tert-butylacrylamide, N-(hydroxymethyl)acrylamide, and 3-acryloyl-2- oxazolidinone. Other acrylamide monomers are also possible.

[0062] In some embodiments, an acrylonitrile monomer comprises a vinylic nitrile moiety. In some embodiments, an acrylonitrile monomer is optionally substituted. In some embodiments, an acrylonitrile monomer is an unsubstituted acrylonitrile monomer. In some embodiments, an acrylonitrile monomer is a substituted acrylonitrile monomer. I n some embodiments, an acrylonitrile monomer is an acrylonitrile monomer optionally substituted at the vinylic position. As used herein, the term (meth) acrylonitrile comprehends both acrylonitrile monomers and methacrylonitrile monomers.

[0063] Methods for forming the structural moieties displayed in formula (I) in the polymer may involve neighboring repeat units able to undergo a cyclization reaction. Such repeat units may be introduced in the polymer by polymerizing monomers according to one or more of formulae (A), (B), or (C): wherein: each instance of Ri is independently a hydrogen or methyl group,

[0064] R3 and R4 are each independently hydrogen, optionally substituted acyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted heteroalkyl, optionally substituted heteroalkenyl, optionally substituted heteroalkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, a nitrogen protecting group when attached to a nitrogen atom, or an oxygen protecting group when attached to an oxygen atom.

[0065] #14695765vl In some embodiments, at least one instance of Ri is methyl. In some embodiments, at least one instance of Ri is hydrogen. In some embodiments, each instance of Ri is methyl. In some embodiments, each instance of Ri is hydrogen.

[0066] In some embodiments, R3 and R4 are the same or different and are each a hydrogen or optionally substituted substituted alkyl or optionally substituted aryl having up to 36 carbon atoms, which may additionally contain oxygen, nitrogen, sulphur and / or phosphorous atoms in the form of typical organic functionalities, such as for example, an ether, alcohol, acid, ester, amide, imide, phosphonic acid, phosphonic ester, phosphoric acid, phosphoric ester, phosphinic acid, phosphinic ester, sulphonic acid, sulphonic ester, sulphinic acid and / or sulphinic ester function, silicon, aluminium and / or boron atoms or halogens, such as fluorine, chlorine, bromine and / or iodine. The following may be mentioned as examples of R3, without being restricted to thereto: methyl, ethyl, propyl, 2-propyl, butyl, tert-butyl, hexyl, ethylhexyl, octyl, dodecyl, octadecyl.

[0067] In some embodiments, Rds hydrogen, optionally substituted acyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted heteroalkyl, optionally substituted heteroalkenyl, optionally substituted heteroalkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, or a nitrogen protecting group when attached to a nitrogen atom.

[0068] In some embodiments, R3 is hydrogen, optionally substituted alkyl, or a nitrogen protecting group. In some embodiments, R3 is hydrogen or a nitrogen protecting group. In some embodiments, R3 is hydrogen. In some embodiments, R3 is a nitrogen protecting group.

[0069] In some embodiments, R3 is optionally substituted acyl.

[0070] In some embodiments, Rds hydrogen or optionally substituted alkyl. In some embodiments, R3 is hydrogen or optionally substituted C1-C36 alkyl. In some embodiments, R3 is hydrogen or optionally substituted C1-C20 alkyl. In some embodiments, Rds hydrogen or optionally substituted Ci-Cs alkyl. In some embodiments, Rds optionally substituted alkyl, optionally substituted alkenyl, or optionally substituted alkynyl. In some embodiments, R3 is optionally substituted alkyl. In some embodiments, Rds optionally substituted C1-C36 alkyl. In some embodiments, R3 is optionally substituted C1-C20 alkyl. In some embodiments, R3 is optionally substituted Ci-Cs alkyl. In some embodiments, Rds methyl, ethyl, propyl, 2-propyl, butyl, tert-butyl, hexyl, ethylhexyl, octyl, dodecyl, octadecyl. In some embodiments, R3 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t-butyl optionally

[0071] #14695765vl substituted with hydroxy or alkoxy. In some embodiments, R3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t-butyl. In some embodiments, R3 is hydrogen, methyl, 2-hydroxyethyl, or isopropyl. In some embodiments, R3 is methyl. In some embodiments, R3 is 2-hydroxyethyl. In some embodiments, R3 is isopropyl.

[0072] In some embodiments, Rds optionally substituted C1-C36 alkenyl. In some embodiments, Rds optionally substituted C1-C20 alkenyl. In some embodiments, Rds optionally substituted Ci-Cs alkenyl. In some embodiments, Rds optionally substituted C1-C36 alkynyl. In some embodiments, Rds optionally substituted C1-C20 alkynyl. In some embodiments, Rds optionally substituted Ci-Cs alkynyl.

[0073] In some embodiments, R3 is optionally substituted heteroalkyl, optionally substituted heteroalkenyl, or optionally substituted heteroalkynyl. In some embodiments, R3 is optionally substituted heteroalkyl. In some embodiments, R3 is optionally substituted C1-C36 heteroalkyl. In some embodiments, Rds optionally substituted C1-C20 heteroalkyl. In some embodiments, R3 is optionally substituted Ci-Cs heteroalkyl. In some embodiments, Rds optionally substituted C1-C36 heteroalkenyl. In some embodiments, Rds optionally substituted C1-C20 heteroalkenyl. In some embodiments, Rds optionally substituted Ci-Cs heteroalkenyl. In some embodiments, Rds optionally substituted C1-C36 heteroalkynyl. In some embodiments, Rds optionally substituted C1-C20 heteroalkynyl. In some embodiments, Rds optionally substituted Ci-Cs heteroalkynyl.

[0074] In some embodiments, R3 is optionally substituted carbocyclyl or optionally substituted heterocyclyl. In some embodiments, Rds optionally substituted carbocyclyl. In some embodiments, Rds optionally substituted C3-C8 carbocyclyl. In some embodiments, Rds optionally substituted C5-C6 carbocyclyl. I n some embodiments, Rds optionally substituted heterocyclyl. In some embodiments, R3 is optionally substituted 3- to 8-membered heterocyclyl.

[0075] In some embodiments, R3 is optionally substituted aryl or optionally substituted heteroaryl. In some embodiments, Rds optionally substituted aryl. In some embodiments, Rds optionally substituted Ce-Cio aryl. In some embodiments, Rds optionally substituted phenyl. In some embodiments, R3 is optionally substituted heteroaryl. In some embodiments, R3 is optionally substituted 5- to 10-membered heterocyclyl. In some embodiments, R3 is optionally substituted 5- to 6-membered heterocyclyl.

[0076] In some embodiments, R4 is hydrogen, optionally substituted acyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted heteroalkyl, optionally substituted heteroalkenyl, optionally substituted heteroalkynyl, optionally

[0077] #14695765vl substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, or an oxygen protecting group when attached to an oxygen atom.

[0078] In some embodiments, R4 is hydrogen, optionally substituted alkyl, or an oxygen protecting group. In some embodiments, R4 is hydrogen or an oxygen protecting group. In some embodiments, R4 is hydrogen. In some embodiments, R4 is an oxygen protecting group.

[0079] In some embodiments, R4is optionally substituted acyl.

[0080] In some embodiments, R4is hydrogen or optionally substituted alkyl. In some embodiments, R4is hydrogen or optionally substituted C1-C36 alkyl. In some embodiments, R4is hydrogen or optionally substituted C1-C20 alkyl. In some embodiments, R4is hydrogen or optionally substituted Ci-Cs alkyl. In some embodiments, R4is optionally substituted alkyl, optionally substituted alkenyl, or optionally substituted alkynyl. In some embodiments, R4 is optionally substituted alkyl. In some embodiments, R4is optionally substituted C1-C36 alkyl. In some embodiments, R4is optionally substituted C1-C20 alkyl. In some embodiments, R4is optionally substituted Ci-Cs alkyl. In some embodiments, R4is methyl, ethyl, propyl, 2-propyl, butyl, tert-butyl, hexyl, ethylhexyl, octyl, dodecyl, octadecyl. In some embodiments, R4 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t-butyl optionally substituted with hydroxy or alkoxy. In some embodiments, R4 is methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t-butyl. In some embodiments, R4 is hydrogen, methyl, 2-hydroxyethyl, or isopropyl. In some embodiments, R4 is methyl. In some embodiments, R4 is 2-hydroxyethyl. In some embodiments, R4 is isopropyl.

[0081] In some embodiments, R4is optionally substituted C1-C36 alkenyl. In some embodiments, R4is optionally substituted C1-C20 alkenyl. In some embodiments, R4is optionally substituted Ci-Cs alkenyl. In some embodiments, R4is optionally substituted C1-C36 alkynyl. In some embodiments, R4is optionally substituted C1-C20 alkynyl. In some embodiments, R4is optionally substituted Ci-Cs alkynyl.

[0082] In some embodiments, R4 is optionally substituted heteroalkyl, optionally substituted heteroalkenyl, or optionally substituted heteroalkynyl. In some embodiments, R4is optionally substituted heteroalkyl. In some embodiments, R4is optionally substituted C1-C36 heteroalkyl. In some embodiments, R4is optionally substituted C1-C20 heteroalkyl. In some embodiments, R4 is optionally substituted Ci-Cs heteroalkyl. In some embodiments, R4is optionally substituted C1-C36 heteroalkenyl. In some embodiments, R4is optionally substituted C1-C20 heteroalkenyl. In some embodiments, R4is optionally substituted Ci-Cs heteroalkenyl. In some embodiments,

[0083] #14695765vl R s optionally substituted C1-C36 heteroalkynyl. In some embodiments, Rds optionally substituted C1-C20 heteroalkynyl. In some embodiments, Rds optionally substituted Ci-Cs heteroalkynyl.

[0084] In some embodiments, R4 is optionally substituted carbocyclyl or optionally substituted heterocyclyl. In some embodiments, Rds optionally substituted carbocyclyl. In some embodiments, Rds optionally substituted C3-C8 carbocyclyl. In some embodiments, Rds optionally substituted C5-C6 carbocyclyl. In some embodiments, Rds optionally substituted heterocyclyl. In some embodiments, R4 is optionally substituted 3- to 8-membered heterocyclyl.

[0085] In some embodiments, R4 is optionally substituted aryl or optionally substituted heteroaryl. In some embodiments, R4is optionally substituted aryl. In some embodiments, R4is optionally substituted Ce-Cio aryl. In some embodiments, R4is optionally substituted phenyl. In some embodiments, R4is optionally substituted heteroaryl. In some embodiments, R4is optionally substituted 5- to 10-membered heterocyclyl. In some embodiments, R4is optionally substituted 5- to 6-membered heterocyclyl.

[0086] In some embodiments, Monomer A represents (meth)acrylic acid and / or (meth) acrylate esters, monomer B represents (meth)acrylamides, monomer C represents (meth)acrylonitriles. Monomers may be used in variable molar ratios. In some embodiments, to facilitate imidization, monomer A is combined with monomer B or C, or a combination of both B and C. In some embodiments, monomer B is used alone, or in combination with monomer A. In some embodiments, monomer C is combined with monomer A.

[0087] In some embodiments, the first step in producing resins is the production of monomer mixtures containing a (meth)acrylic acid or (meth)acrylic ester, or combination thereof, with a (meth) acrylamide or (meth)acrylonitrile, or combination thereof. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylate monomer, an optionally substituted acrylamide monomer, and / or an optionally substituted acrylonitrile monomer. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylic ester monomer, an optionally substituted methacrylic ester monomer, an acrylic acid monomer, a methacrylic acid monomer, an optionally substituted acrylamide monomer, an optionally substituted methacrylamide monomer, an acrylonitrile monomer, and / or a methacrylonitrile monomer. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylonitrile and an optionally substituted acrylic acid. In some embodiments, the plurality of monomer molecules comprises acrylonitrile and acrylic acid. In some embodiments, the plurality of monomer molecules comprises methacrylonitrile and

[0088] #14695765vl acrylic acid. In some embodiments, the plurality of monomer molecules comprises acrylonitrile and methacrylic acid. In some embodiments, the plurality of monomer molecules comprises methacrylonitrile and methacrylic acid. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylonitrile and an optionally substituted acrylic ester. In some embodiments, the plurality of monomer molecules comprises acrylonitrile and an optionally substituted acrylic ester. In some embodiments, the plurality of monomer molecules comprises methacrylonitrile and an optionally substituted acrylic ester.

[0089] It was found that completely substituting the (meth)acrylonitrile monomer with (meth)acrylamide may result in poly(meth)acrylimide materials with improved thermomechanical properties, and / or may avoid the toxicological concerns related to (meth)acrylonitrile. Accordingly, in some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylamide monomer, an optionally substituted acrylic ester monomer, and / or an optionally substituted acrylic acid monomer. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylic ester monomer, an optionally substituted methacrylic ester monomer, an acrylic acid monomer, a methacrylic acid monomer, an optionally substituted acrylamide monomer, and / or an optionally substituted methacrylamide monomer. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylate monomer and an optionally substituted acrylamide monomer. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylamide and an optionally substituted acrylic ester. In some embodiments, the plurality of monomer molecules comprises an optionally substituted acrylamide and an optionally substituted acrylic acid. In some embodiments, the plurality of monomer molecules comprises methacrylic acid and methacrylamide.

[0090] In some embodiments, the molar ratio of an optionally substituted acrylate monomer to an optionally substituted acrylamide monomer is between 10:90 and 90:10. In some embodiments, the molar ratio of an optionally substituted acrylate monomer to an optionally substituted acrylamide monomer is between 20:80 and 80:20. In some embodiments, the molar ratio of an optionally substituted acrylate monomer to an optionally substituted acrylamide monomer is between 40:60 and 60:40. In some embodiments, the molar ratio of an optionally substituted acrylate monomer to an optionally substituted acrylamide monomer is between 45:55 and 55:45. In some embodiments, the molar ratio of an optionally substituted acrylate monomer to an optionally substituted acrylamide monomer is between 49:51 and 51:49. In one embodiment, the molar ratio of (meth)acrylic acid monomer to (meth)acrylamide as main

[0091] #14695765vl constituents is between 20:80 and 80:20. In some embodiments, the molar ratio of (meth)acrylic acid monomer to (meth) acrylamide as main constituents is between 40:60 and 60:40. In some embodiments, the molar ratio of (meth)acrylic acid monomer to (meth)acrylamide as main constituents is between 51:49 to 49:51. In one embodiment, the molar ratio of (meth)acrylic ester monomer to (meth) acrylamide as main constituents is between 20:80 and 80:20. In some embodiments, the molar ratio of (meth)acrylic ester monomer to (meth) acrylamide as main constituents is between 40:60 and 60:40. In some embodiments, the molar ratio of (meth)acrylic ester monomer to (meth) acrylamide as main constituents is between 51:49 to 49:51.

[0092] Additional suitable comonomers may be used be used such as esters of acrylic or methacrylic acid, N-substituted (meth)acrylamides vinyl ethers, styrenes, acrylamides, maleimides, vinyl esters, vinylpyrrolidone, vinylic cyclic structures such as but not limited to vinyl acetal, vinyl ethers, spiro-ortho-carbonates, spiro-ortho-esters, vinyl sulfones, allylic sulfides, vinyl oxirane, ketene acetals, thionolactones. These comonomers are intended as examples and are not limiting. In some embodiments, the proportion of comonomers does not amount to more than 50% by weight of the two main constituents. In some embodiments, the proportion of comonomers does not amount to more than 40% by weight of the two main constituents. In some embodiments, the proportion of comonomers does not amount to more than 35% by weight of the two main constituents. In some embodiments, the proportion of comonomers does not amount to more than 20% by weight of the two main constituents. In some embodiments, the proportion of comonomers does not amount to more than 10% by weight of the two main constituents. In some embodiments, the additional comonomers comprise less than 50 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise less than 35 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise less than 20 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise less than 10 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise less than 5 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 1 mol% to 50 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 1 mol% to 35 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 1 mol% to 20 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 1 mol% to 10 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 1 mol% to 5 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 5 mol% to 50 mol% of the reaction mixture. In some

[0093] #14695765vl embodiments, the additional comonomers comprise 5 mol% to 35 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 5 mol% to 20 mol% of the reaction mixture. In some embodiments, the additional comonomers comprise 5 mol% to 10 mol% of the reaction mixture.

[0094] In some embodiments, the reaction mixture further comprises one or more cross -linkers. In some embodiments, a cross-linker links one polymer chain to at least one other polymer chain, e.g., via one or more covalent bonds. In some embodiments, a cross-linker comprises two or more functional groups that may react to link one polymer chain to at least one other polymer chain. In some embodiments, a cross-linker is a comonomer comprising two or more polymerizable moieties. In some embodiments, a cross-linker comprises two or more vinylic moieties. In some embodiments, a cross-linker comprises two or more acylate, acrylamide, and / or acrylonitrile moieties. The terms “cross-linker, “crosslinking monomer,” “crosslinking molecule,” and “crosslinking agent” are used interchangeably herein.

[0095] Small amounts of crosslinking unsaturated monomers can be used, having at least two 2 polymerizable functionalities in the molecule. In some embodiments, the cross-linker comprises at least two polymerizable functionalities in the molecule (e.g., at least two vinylic groups). In some embodiments, the cross-liner comprises two, three, or four polymerizable functionalities in the molecule. In some embodiments, the cross-linker comprises the same polymerizable functionalities as the plurality of monomer molecules. In some embodiments, the cross-linker comprises two or more polymerizable functionalities selected from an optionally substituted acrylate, an optionally substituted acrylamide, and / or an optionally substituted acrylonitrile. In some embodiments, the cross-linker comprises two or more polymerizable functionalities selected from an optionally substituted acrylate or an optionally substituted acrylamide.

[0096] Examples of cross-linkers include, but are not limited to, butanediol di(meth)acrylate, triallylisocyanurate, triacrylate isocyanurates (IGM Photomer 4356), pentaerythritol triacrylate, ethylene glycol acrylate, ethylene glycol methacrylate, triethylene glycol diacrylate, and triethylene glycol dimethacrylate. Unsaturated polymerizable oligomers or polymers having at least two 2 polymerizable functionalities may be used, for example but not limited to aliphatic urethane diacrylate or dimethacrylate oligomer (IGM Photomer 6024, Sartomer CN9009, CN1964, CN9039), polyester acrylate oligomer (Allnex Ebecryl 830). Ionic crosslinking agents composed of polyvalent metal ions bound to polymerizable units such as but not limited to (meth)acrylic acids, with preference given to magnesium (meth) acrylate or zinc (meth)acrylates may also be used. In some embodiments, the one or more cross-linkers comprise ethylene

[0097] #14695765vl glycol dimethacrylate, CN9009, or Photomer 4356. In some embodiments, the one or more cross-linkers comprise N-methacryloylmethacrylamide or N-acryloylacrylamide.

[0098] In some embodiments, the amounts of crosslinking molecules used is 0 to 20% by weight. In some embodiments, the amounts of crosslinking molecules used is 0 to 10% by weight. In some embodiments, the amounts of crosslinking molecules used is 0.05% to 5.0% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 80% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 70% by weight. In some embodiments, the reaction mixture comprises crosslinker in an amount of 0% to 60% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 50% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 40% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 30% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 20% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 15% by weight. In some embodiments, the reaction mixture comprises crosslinker in an amount of 0% to 10% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0% to 5% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 80% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 70% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 60% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 50% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 40% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 30% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 20% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 15% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 10% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 0.5% to 5% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 80% by weight. In some embodiments, the reaction mixture comprises crosslinker in an amount of 1% to 70% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 60% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 50% by weight. In some

[0099] #14695765vl embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 40% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 30% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 20% by weight. In some embodiments, the reaction mixture comprises crosslinker in an amount of 1% to 15% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 10% by weight. In some embodiments, the reaction mixture comprises cross-linker in an amount of 1% to 5% by weight.

[0100] In certain embodiments, the polymer resin (e.g., polymer resin 111) comprises one or more initiators. The initiator is a substance or molecule that initiates a reaction, such as in polymerization. Typically, the initiator decomposes to form radical, anionic, or cationic species that serve as reactive sites for propagation of polymerization. In some embodiments, the initiator initiates free radical polymerization. Suitable additives and initiators are described herein in greater detail.

[0101] In certain embodiments, the polymer resin (e.g., polymer resin 111) comprises a photoinitiator. In some embodiments, the photoinitiator generates a reactive species when exposed to radiation (e.g., actinic radiation, electromagnetic radiation, electron beam radiation). In some embodiments, the photoinitiator is a molecule that generates a free radical species when exposed to radiation. In some embodiments, the free radical species formed from the photoinitiator initiates polymerization of one or more monomers, co-monomers, and / or oligomers.

[0102] The photoinitiator may be any of a variety of suitable photoinitiators. In some embodiments, for example, the photoinitiator comprises a Type I photoinitiator and / or a Type II photoinitiator. In certain embodiments, the Type I photoinitiator is an initiator that undergoes direct bond cleavage upon radiation absorption to produce a free radical species that initiates polymerization of one or more monomers, co-monomers, and / or oligomers. In some embodiments, the Type II photoinitiator is an initiator that produces a free radical species through a hydrogen-abstraction or electron-transfer reaction with a separate co-initiator after radiation absorption.

[0103] In certain embodiments, the photoinitiator comprises a benzoin ether, a benzil ketal, an a-dialkoxy-acetophenone, an a-hydroxy-alkylphenone, an a-amino alkylphenone, an acyl phosphine oxide, a benzophenone, a thioxanthone, and / or a metallocene. According to some embodiments, the photoinitiator comprises acetophenone, anisoin, anthraquinone, anthraquinone-2-sulfonic acid, benzene tricarbonylchromium, benzil, benzoin, benzoin ethyl

[0104] #14695765vl ether, benzoin methyl ether, benzophenone, 1 -hydroxycyclohexyl phenyl ketone, 3, 3’, 4,4’- benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4’- morpholinobutyrophenone, 4,4’ -bis(diethylamino)benzophenone, 4,4’ - bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthene-9-one, (cumene)cyclopentadienyl iron(ii) hexafluorophosphate, dibenzosuberenone, 2,2- diethoxyacetophenone, 4,4’ -dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4- (dimethylamino)benzophenone, 4,4’ -dimethylbenzil, 2,5-dimethylbenzophenone, 3,4- dimethylbenzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2- methylpropiophenone, 4’ -ethoxyacetophenone, 2-ethylanthraquinone, ferrocene, 3’- hydroxyacetophenone, 4’ -hydroxyacetophenone, 3 -hydroxybenzophenone, 4- hydroxybenzophenone, 1 -hydroxycyclohexyl phenyl ketone, 2-hydroxy-2- methylpropiophenone, 2-methylbenzophenone, 3 -methylbenzophenone, methylbenzoylformate, 2-methyl-4’-(methylthio)-2-morpholinopropiophenone, phenanthrenequinone, 4’- phenoxyacetophenone, thioxanthene-9-one, triarylsulfonium hexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide, 2,4,6-trimethylbenzoylphenyl phosphinate, bis(2,6-dimethoxybenzoyl)-2,4,4- trimethylpentylphosphine oxide, diphenyl (2, 4, 6-trimethylbenzoyl)phosphine oxide, alphahydroxycyclohexyl phenyl ketone, 2-hydroxy-l-(4-(4-(2-hydroxy-2- methy|propionyl)benzyl)phenyl-2-methy|propan-l-one,2-hydroxy-2-methyl-l- phenylpropanone,2-hydroxy-2-methyl-l-(4-isopropylphenyl)propanone,oligo(2-hydroxy-2- methyl- 1 - (4- ( 1 -methyl vinyl)phenyl)propanone, 2-hydroxy-2-methyl- 1 - (4- dodecylphenyl)propanone,2-hydroxy-2-methyl-l-[(2- hydroxyethoxy)pheny]]propanone, benzophenone, substituted benzophenones, and mixtures of any two or more thereof. Other photoinitiators are also possible. In some embodiments, the one or more photoinitiators comprise diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and combinations of two or more thereof. In some embodiments, the one or more photoinitiators comprise diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.

[0105] According to some embodiments, the photoinitiator comprises a salt. In some embodiments, the photoinitiator comprises an onium salt, an iodonium salt, and / or a sulfonium salt. In some embodiments, the photoinitiator comprises an iodonium salt or a sulfonium salt of formula (RA)2I+XA " or (RA)SS+XA wherein each instance of RAis independently optionally substituted Ce-io aryl or optionally substituted Ci-io alkyl; and XA is a counter ion. In some embodiments, the photoinitiator comprises bis(2,4,6-trimethylpyridine)iodonium

[0106] #14695765vl hexafluorophosphate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, bis(4- bromophenyl)iodonium trifluoromethanesulfonate, bis(2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, (3-bromophenyl)(mesityl)iodonium trifluoromethanesulfonate, bis(4- tert-butylphenyl)iodonium tetrafluoroborate, bis(4-tert-butylphenyl)iodonium nonafluoro- 1- butanesulfonate, bis(4-tert-butylphenyl)iodonium chloride, diphenyliodonium perchlorate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium chloride, diphenyliodonium bromide, diphenyliodonium-2-carboxylate monohydrate, 4-isopropyl-4'- methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, (2-methylphenyl)(2,4,6- trimethylphenyl)iodonium trifluoromethanesulfonate, (3-methylphenyl)(2,4,6- trimethylphenyl)iodonium trifluoromethanesulfonate, (4-methylphenyl)(2,4,6- trimethylphenyl)iodonium trifluoromethanesulfonate, (4-Nitrophenyl)(phenyl)iodonium trifluoromethanesulfonate, Phenyl[3-(trifluoromethyl)phenyl]iodonium trifluoromethanesulfonate, [3-(trifluoromethyl)phenyl](2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, [4-(trifluoromethyl)phenyl](2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, bis(4-fluorophenyl)iodonium trifluoromethanesulfonate, diphenyliodonium hexafluorophosphate, [4-fhioro-3-(trifhioromethyl)phenyl] (2,4,6- trimethoxyphenyl)iodonium p-toluenesulfonate, bis(pyridine)iodonium tetrafluoroborate, 4- biphenylyl(2,4,6-trimethoxyphenyl)iodonium trifluoromethanesulfonate, (3,5- dichlorophenyl)(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, (5-fluoro-2- nitrophenyl)(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, [(4- trifhioromethyl)phenyl](2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, phenyl(2,4,6- trimethoxyphenyl)iodonium p-toluenesulfonate, [4-(bromomethyl)phenyl] (2,4,6- trimethoxyphenyl)iodonium p-toluenesulfonate, and / or diphenyliodonium nitrate.

[0107] According to some embodiments, the polymer resin (e.g., polymer resin 111) comprises a thermal initiator. In some embodiments, the thermal initiator generates a reactive species when exposed to thermal energy. In some embodiments, the thermal initiator generates a free radical species when exposed to radiation. In some embodiments, the free radical species formed from the thermal initiator initiates polymerization of one or more monomers, comonomers, and / or oligomers.

[0108] The thermal initiator may be any of a variety of suitable thermal initiators. According to some embodiments, for example, the thermal initiator comprises an organic peroxide, an azocompound, a persulfate, a nitroxide- generating species, and / or an organosulfur radical source. In some embodiments, the thermal initiator is one or more of tert-amyl peroxybenzoate, 4,4-

[0109] #14695765vl azobis(4-cyanovaleric acid), 1,1’ -azobis(cyclohexanecarbonitrile), 2,2’ -azobisisobutyronitrile, benzoyl peroxide, 2,2-bis(tert-butylperoxy)butane, l,l-bis(tert-butylperoxy)cyclohexane, 2,5- bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, bis(l-(tert-butylperoxy)-l-methylethyl)benzene, l,l-bis(tert-butylperoxy)-3,3,5- trimethylcyclohexane, tert-butyl hydroperoxide, tert-butyl peracetate, tert-butyl peroxide, tertbutyl peroxybenzoate, tert-butylperoxy isopropyl carbonate, cumene hydroperoxide, cyclohexanone peroxide, dicumyl peroxide, lauroyl peroxide, 2,4-pentanedione peroxide, peracetic acid, and / or potassium persulfate. Other thermal initiators are also possible.

[0110] The polymer resin may comprise the initiator (e.g., photoinitiator, thermal initiator) in any of a variety of suitable amounts. In certain embodiments, for example, the polymer resin comprises the initiator in an amount greater than or equal to 0.1%, greater than or equal to 0.5%, greater than or equal to 1%, greater than or equal to 5%, greater than or equal to 8%, or greater than or equal to 10% of the polymer resin by weight. In some embodiments, the polymer resin comprises the initiator in an amount less than or equal to 15%, less than or equal to 10%, less than or equal to 8%, less than or equal to 5%, less than or equal to 1%, or less than or equal to 0.5% of the polymer resin by weight. Combinations of the above recited ranges are also possible (e.g., the polymer resin comprises the initiator in an amount greater than or equal to 0.1% and less than or equal to 15% of the polymer resin by weight). Other ranges are also possible. In some embodiments, the polymer resin comprises at least one photoinitiator in an amount of greater than or equal to 0.1% and less than or equal to 15% of the polymer resin by weight, preferably greater than or equal to 0.5% and less than or equal to 10% of the polymer resin by weight, more preferably greater than or equal to 1% and less than or equal to 8% of the polymer resin by weight, and more preferably greater than or equal to 1% and less than or equal to 5% of the polymer resin by weight.

[0111] According to certain embodiments, the polymer resin (e.g., polymer resin 111) comprises a NIR dye. The NIR dye may be any of a variety of suitable NIR dyes. In certain embodiments, for example, the NIR dye comprises a cyanine dye, a phthalocyanine dye, a porphyrin dye, a squaraine dye, a squarylium dye, a diimonium dye, and / or a dithiolene complex. In some embodiments, the NIR dye is a NIR borate dye or a NIR heat generating dye. In certain embodiments, the NIR dye is IR-813, IR-140, IR-780, IR-783, IR-1601, Indocyanine Green, IRMO, IR-780, S2425, S0507, S2544, S0991, S2025, camphorquinone, ethyldimethylaminobenzoate, SQ-1, SQ-2, SQ-3, BODIPY, or a salt thereof. Other NIR dyes are also possible.

[0112] #14695765vl The polymer resin may comprise the NIR dye in any of a variety of suitable amounts. In some embodiments, for example, the polymer resin comprises the NIR dye in an amount greater than or equal to 0.01%, greater than or equal to 0.05%, greater than or equal to 0.1%, greater than or equal to 0.2%, greater than or equal to 0.3%, greater than or equal to 0.4%, greater than or equal to 0.5%, greater than or equal to 1%, greater than or equal to 2%, greater than or equal to 3%, or greater than or equal to 4% by weight of the polymer resin. In certain embodiments, the polymer resin comprises the NIR dye in an amount less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, less than or equal to 1%, less than or equal to 0.5%, less than or equal to 0.4%, less than or equal to 0.3%, less than or equal to 0.2%, less than or equal to 0.1%, or less than or equal to 0.05% by weight of the polymer resin. Combinations of the above recited ranges are possible (e.g., the polymer resin comprises the NIR dye in an amount greater than or equal to 0.01% and less than or equal to 1% by weight of the polymer resin). Other ranges are also possible.

[0113] In some embodiments, the polymer resin (e.g., polymer resin 111) comprises an optional reducing agent. In some embodiments, the reducing agent comprises a phosphine-based reducing agent or an amine-based reducing agent. In some embodiments, the reducing agent comprises 4-(diphenylphosphino)benzoic acid, 2-diphenylphosphinobenzoic acid, bis(2- diphenylphosphinophenyl) -ether, triomethoxyphenylphosphine, DPBP bidentate phosphine, 4- dimethylaminophenyldiphenylphosphine, (R,R) dach phenyl trost, triphenylphosphine, ethyl 4- dimethylaminobenzoate, 4-(dimethylamino)phenylacetic acid, triphenylamine, N,N- dibutylaniline, N-ethyl-N-isopropylaniline, and / or 3-(dimethylamino)benzyl alcohol.

[0114] In certain embodiments, the polymer resin comprises a photoredox system comprising a NIR dye, a salt initiator, and optionally a reducing agent. In certain embodiments, the photoredox system is configured to initiate polymerization of the polymer resin upon exposure to IR (e.g., NIR) electromagnetic radiation. In some embodiments, the NIR dye acts as a sensitizer together with the salt initiator. For example, in some embodiments, the NIR dye absorbs IR (e.g., NIR) electromagnetic radiation and undergoes an excited-state transition that promotes electron transfer to the salt initiator, thereby generating a reactive species capable of initiating polymerization. In some embodiments, the optional reducing agent is configured to restore the catalytic cycle by regenerating the ground-state sensitizer.

[0115] According to some embodiments, the polymer resin (e.g., polymer resin 111) comprises a photothermal agent. In certain embodiments, the photothermal agent is configured to absorb NIR electromagnetic radiation.

[0116] #14695765vl The photothermal agent may be any of a variety of suitable species. In some embodiments, for example, the photothermal agent comprises a plasmonic nanostructures (e.g., gold nanorods, gold nanostars, gold nanoshells, gold nanoplates, copper sulfide nanoparticles, copper selenide nanoparticles, and / or other copper-based chalcogenides), a semiconductor (e.g., molybdenum disulfide, tungsten disulfide, bismuth sulfide, tin sulfide, tin selenide, lead sulfide, copper iron sulfide, and / or other metal chalcogenides), metal oxides (e.g., reduced tungsten oxide, reduced titanium oxide, reduced niobium oxide, and / or reduced molybdenum oxide), carbon-based NIR absorbers (e.g., graphene, reduced graphene oxide, graphene nanoplatelets, carbon nanotubes, carbon black, amorphous carbon, and / or fullerenes), two-dimensional metal carbides and / or nitrides, black phosphorus and / or phosphorene derivatives, and / or conjugated polymers (e.g., including polydopamine, polypyrrole, and / or polyaniline). Other photothermal agents are also possible.

[0117] The polymer resin may comprise the photothermal agent in any of a variety of suitable amounts. In some embodiments, for example, the polymer resin comprises the photo thermal agent in an amount greater than 0%, greater than or equal to 0.001%, greater than or equal to 0.005%, greater than or equal to 0.01%, greater than or equal to 0.05%, greater than or equal to 0.1%, greater than or equal to 0.2%, greater than or equal to 0.3%, greater than or equal to 0.4%, greater than or equal to 0.5%, greater than or equal to 1%, greater than or equal to 2%, greater than or equal to 3%, greater than or equal to 4%, greater than or equal to 5%, greater than or equal to 10%, or greater than or equal to 15% by weight of the polymer resin. In certain embodiments, the polymer resin comprises the photo thermal agent in an amount less than or equal to 20%, less than or equal to 15%, less than or equal to 10%, less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, less than or equal to 1%, less than or equal to 0.5%, less than or equal to 0.4%, less than or equal to 0.3%, less than or equal to 0.2%, less than or equal to 0.1%, or less than or equal to 0.05% by weight of the polymer resin. Combinations of the above recited ranges are possible (e.g., the polymer resin comprises the photothermal agent in an amount greater than 0% and less than or equal to 20% by weight of the polymer resin, the polymer resin comprises the photothermal agent in an amount greater than or equal to 0.001% and less than or equal to 20% by weight of the polymer resin). Other ranges are also possible.

[0118] The polymer resin (e.g., polymer resin 111) may have any of a variety of suitable viscosities (e.g., dynamic viscosities). In certain embodiments, the polymer resin has a viscosity of at least 10 cPs, at least 50 cPs, at least 90 cPs, at least 100 cPs, at least 200 cPs, at least 300

[0119] #14695765vl cPs, at least 400 cPs, at least 500 cPs, at least 600 cPs, at least 700 cPs, at least 800 cPs, at least 900 cPs, at least 1,000 cPs, at least 1,100 cPs, at least 1,200 cPs, at least 1,300 cPs, at least 1,400 cPs, at least 1,500 cPs, at least 2,000 cPs, at least 3,000 cPs, at least 4,000 cPs, at least 5,000 cPs, at least 10,000 cPs, at least 20,000 cPs, at least 30,000 cPs, at least 40,000 cPs, at least 50,000 cPs, at least 100,000 cPs, at least 200,000 cPs, at least 500,000 cPs, or greater, at 25 °C. In some embodiments, the polymer resin has a viscosity of less than or equal to less than 1,000,000 cPs, less than or equal to 200,000 cPs, less than or equal to 100,000 cPs, less than or equal to 50,000 cPs, less than or equal to 40,000 cPs, less than or equal to 30,000 cPs, less than or equal to 20,000 cPs, less than or equal to 10,000 cPs, less than or equal to 5,000 cPs, less than or equal to 4,000 cPs, less than or equal to 3,000 cPs, less than or equal to 2,000 cPs, less than or equal to

[0120] 1,500 cPs, less than or equal to 1,400 cPs, less than or equal to 1,300 cPs, less than or equal to

[0121] 1,200 cPs, less than or equal to 1,100 cPs, less than or equal to 1,000 cPs, less than or equal to

[0122] 900 cPs, less than or equal to 800 cPs, less than or equal to 700 cPs, less than or equal to 600 cPs, less than or equal to 500 cPs, less than or equal to 400 cPs, less than or equal to 300 cPs, less than or equal to 200 cPs, less than or equal to 100 cPs, less than or equal to 90 cPs, or less than or equal to 50 cPs at 25 °C. Combinations of the above recited ranges are possible (e.g., the polymer resin has a viscosity of at least 10 cPs and less than or equal to 1,000,000 cPs at 25 °C). Other ranges are also possible.

[0123] In certain embodiments, the viscosity of the polymer resin is measured by ASTM D2196 (2020) at 25 °C using a rotational viscometer. In certain non-limiting embodiments, the rotational viscometer is an Anton Paar ViscoQC with a RH3 spindle at 100 rotations per minute (rpm).

[0124] According to certain embodiments, the viscosity of the polymer resin may be tuned for a particular processing technique. In some embodiments, tuning the viscosity of the polymer resin for a particular processing technique may advantageously control the flow or resin during impregnation of the plurality of fibers.

[0125] In certain embodiments, the polymer resin (e.g., polymer resin 111) may comprise one or more rheological modifiers. In some embodiments, the one or more rheological modifiers may be used to tune the viscosity of the polymer resin.

[0126] According to some embodiments, the rheological modifier comprises an inorganic modifier, an organic modifier, an organometallic and / or chelate-based modifier, and / or a fibrous modifier. In certain embodiments, the inorganic modifier comprises fumed silica (e.g., hydrophilic or hydrophobic fumed silica), precipitated silica, organoclays, smectite clays, kaolin,

[0127] #14695765vl talc, mica, calcium carbonate (e.g., precipitated or ground c, coated or uncoated), magnesium carbonate, barium sulfate, aluminum silicate, diatomaceous earth, and / or wollastonite. In some embodiments, the organic modifier comprises hydrogenated castor oil and / or derivatives thereof, polyamide waxes and modified polyamides, modified polyureas, overbased calcium sulfonates and / or other metal sulfonates, oxidized polyethylene waxes, cellulose derivatives (e.g., methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, ethyl hydroxyethyl cellulose, amd / or methyl hydroxypropyl cellulose), natural and modified natural gums (e.g., xanthan gum, guar gum, hydroxypropyl guar, welan gum, diutan gum, rhamsan gum, gum arabic, locust bean gum, carrageenan, and / or alginates), associative thickeners such as hydrophobically modified ethoxylated urethanes (HEUR), hydrophobically modified alkali- swellable emulsions (HASE), hydrophobically modified hydroxyethyl cellulose (HMHEC), and hydrophobically modified polyacrylamides, non-associative alkali- swellable acrylic emulsions (ASE), polyvinyl pyrrolidone (PVP), polyvinyl alcohol, styrene-maleic anhydride copolymers, polyacrylic acid and / or salts thereof, polymethacrylic acid and / or salts thereof, styrene-butadiene rubbers, and / or ethylene- vinyl acetate copolymers. In some embodiments, the organometallic and / or chelate-based modifier comprises organotitanates, organozirconates, aluminum chelates, and zirconium chelates. In some embodiments, the fibrous modifier comprises cellulosic fibers, polyolefin fibers (e.g., polyethylene or polypropylene fibers), polyacrylonitrile fibers, glass fibers, carbon fibers, and / or basalt fibers. Other rheological modifiers, including other inorganic modifiers, organic modifiers, organometallic and / or chelate-based modifiers, and / or fibrous modifiers are also possible.

[0128] Further additional substances, which are different from the stated monomers, crosslinkers, initiators, NIR dyes, photothermal agents, and / or rheological modifiers can be admixed in the formulations (e.g., dispersed therein). Suitable amounts of additives can be for instance between 0% and 20% by weight of the polymer resin. Additives can include, but are not limited to, antioxidants, dyes, thickeners, lubricants, fillers, UV absorbers, plasticizers, organic phosphorous compounds, release agents, flame retardants, graphite, graphene, glass beads or spheres, aluminum particles, and piezo electric-responsive fillers.

[0129] In some embodiments, the additive is present in an amount between 0% and 80% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 70% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 60% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 50% by weight of the

[0130] #14695765vl polymer resin. In some embodiments, the additive is present in an amount between 0% and 40% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 30% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 20% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 15% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 10% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0% and 5% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 80% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 70% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 60% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 50% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 40% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 30% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 20% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 15% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 10% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 0.5% and 5% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 5% and 10% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 10% and 15% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 15% and 20% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 20% and 30% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 30% and 40% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 40% and 50% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 50% and 60% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 60% and 70% by weight of the polymer resin. In some embodiments, the additive is present in an amount between 70% and 80% by weight of the polymer resin.

[0131] #14695765vl In some embodiments, the reaction mixture further comprises one or more solvents. The composition may optionally contain a solvent. Some solvents may enhance the homogeneity of the mixture at ambient temperature. In some embodiments, suitable solvents include those which are capable of volatilization during subsequent processing steps and which do not negatively affect the monomer copolymerization. In some embodiments, suitable solvents include water, which is believed to not negatively affect the safety profile of the mixture. In some embodiments, the one or more solvents comprises a polar solvent. In some embodiments, the one or more solvents comprises a polar protic solvent. In some embodiments, the one or more solvents comprises a polar aprotic solvent. In some embodiments, the one or more solvents comprise water. In some embodiments, the one or more solvents comprises glycerol. In some embodiments, the one or more solvents comprises a non-polar solvent. In some embodiments, the one or more solvents comprises toluene, benzene, cyclohexane, heptane, hexane, or pentane. In some embodiments, the one or more solvents comprises toluene, cyclohexane, or heptane.

[0132] In some embodiments, the one or more solvents comprise 0% to 35% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 0.1% to 35% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 1% to 35% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 5% to 35% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 1% to 20% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 5% to 20% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 1% to 5% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 5% to 10% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 8% to 20% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 8% to 15% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 8% to 12% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 10% to 20% of the reaction mixture by weight. In some embodiments, the one or more solvents comprise 20% to 35% of the reaction mixture by weight.

[0133] In some embodiments, the reaction mixture further comprises one or more blowing agents. In some embodiments, a blowing agent comprises a compound which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo

[0134] #14695765vl hardening or phase transition. In some embodiments, the blowing agent is a substance that forms gas during the hardening or phase transition.

[0135] In some embodiments, the blowing agent causes foaming through a physical process. In some embodiments, the blowing agent is a volatile substance that forms gas when heated. In some embodiments, the blowing agent is added to a reaction mixture and / or a polymer (e.g., a precursor polymer) as an exogenous liquid or gaseous compound. In some embodiments, the one or more blowing agents is added to the reaction mixture as an exogenous liquid or gaseous compound. In some embodiments, the one or more blowing agents is added to the precursor polymer as an exogenous liquid or gaseous compound. In some embodiments, the blowing agent is an expandable bead (e.g., a microsphere encapsulating a gas). In some embodiments, the blowing agent is added to a reaction mixture and / or a polymer (e.g., a precursor polymer) as an expandable bead. In some embodiments, the one or more blowing agents is added to the reaction mixture as an expandable bead. In some embodiments, the one or more blowing agents is added to the precursor polymer as an expandable bead. Expandable beads include, but are not limited to, acrylic shells or micro-balloons (e.g., Advancell Expandable Microspheres) and thermoplastic microspheres (e.g., Expancel® microspheres).

[0136] In some embodiments, the blowing agent causes foaming through a chemical process. In some embodiments, the blowing agents causes foaming through a chemical reaction that produces a small molecule (e.g., a volatile small molecule). In some embodiments, the blowing agent is generated during imidization of a precursor polymer described herein.

[0137] In some embodiments, a mixture for the copolymerisation further contains blowing agents which either decompose or vaporise at temperatures of about 120 °C to 250 °C, forming a gas phase in the process. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below the imidization temperature. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 170 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 160 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 150 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 150 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 140 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature below 130 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above the imidization temperature. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 130 °C. In some embodiments, the blowing agent decomposes or vaporizes at

[0138] #14695765vl a temperature above 140 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 150 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 160 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 170 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 180 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 190 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 290 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 225 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above 250 °C. In some embodiments, the blowing agent decomposes or vaporizes at a temperature above Tgof the precursor polymer.

[0139] In some embodiments, the one or more blowing agents comprise urea, monomethylurea, N,N’ -dimethylurea, formamide, monomethylformamide, formic acid, water, an alcohol, a low molecular weight hydrocarbon, a low molecular weight halohydrocarbon, an organic carboxylic acid, liquid carbon dioxide, azodicarbonamide, and / or hydrazine. Examples of suitable blowing agents include, but are not limited to, the following compounds, or mixtures thereof: nitrogenous compounds, urea, monomethylurea or N,N'-dimethylurea, formamide or monomethylformamide. Further possible, nitrogen-free blowing agents include formic acid, water or mono hydric aliphatic alcohols particularly those of three to eight carbon atoms, for example propan- l-ol, propan-2-ol, butan-2-ol, tert-butanol and isobutanol. Organic carboxylic acids may include oxalic acid, maleic acid, citric acid, itaconic acid, hydroxyisobutyric acid, malonic acid. In some embodiments, the one or more blowing agents comprise urea. In some embodiments, the blowing agent is generated during imidization of the precursor polymer. In some embodiments, the blowing agent is generated during imidization of the precursor polymer by liberation of a small molecule byproduct of imidization. Blowing agents in the form of unsaturated copolymerisable monomers, such as tert-butyl(meth)acrylate, sec-butyl(meth)acrylate and isopropyl(meth)acrylate may also be used.

[0140] The blowing agents may be used in amounts of 0% to 20% by weight based on the monomers used and the desired density of the poly(meth)acrylimide material. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 20% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 15% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in

[0141] #14695765vl an amount of 0% to 10% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 5% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 20% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 15% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 10% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 5% by weight relative to the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 5% to 10% by weight of the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 10% to 15% by weight of the plurality of monomer molecules. In some embodiments, the reaction mixture comprises blowing agent in an amount of 15% to 20% by weight of the plurality of monomer molecules.

[0142] In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 80% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 60% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 40% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0% to 20% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 80% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 60% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 40% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 0.5% to 20% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 5% to 80% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 5% to 60% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 5% to 40% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 5% to 20% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 20% to 40% by volume. In some embodiments, the reaction mixture comprises blowing agent in an amount of 40% to 60% by volume. In some

[0143] #14695765vl embodiments, the reaction mixture comprises blowing agent in an amount of 60% to 80% by volume.

[0144] According to some embodiments, one or more additives described herein (e.g., an initiator, a NIR dye, a photothermal agent, a rheological modifier, a blowing agent, etc.) may be added to the polymer resin prior to impregnating the polymer resin into the plurality of fibers. In certain embodiments, one or more additives described herein (e.g., an initiator, a NIR dye, a photothermal agent, a rheological modifier, a blowing agent etc.) may be added to the polymer resin after impregnating the polymer resin into the plurality of fibers.

[0145] The monomer compositions may include oligomeric and / or polymeric resins of suitable molecular weights to assist in the formation of poly(meth)acrylimide resins and / or foams. These include, for example, PMMA (polymethylmethacrylate) and / or PMMI (poly-N- methylmethacrylimide). Such polymers are believed to have good incorporability. In some embodiments, the syrup phase resulting from addition of PMMA can be realized by means of high molecular weight PMMA, which may be prepared by emulsion or solution polymerization. For example, the product Degalan BT 310 produced by Rohm may serve for this purpose. In some embodiments, the amount of dissolved PMMA is between 0.005 and 0.10 gram of PMMA per gram of monomer mixture which acts as a solvent.

[0146] In some embodiments, the reaction mixture further comprises an oligomer, polymer, or copolymer. In some embodiments, the reaction mixture further comprises one or more of PMMA, PMMI, Degalan BT 310, or Elvacite. In some embodiments, the reaction mixture further comprises a vinylic copolymer. In some embodiments, the reaction mixture further comprises a polyvinylbutyrate.

[0147] In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.001 g to 0.60 g per gram of monomer mixture. In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.001 g to 0.50 g per gram of monomer mixture. In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.001 g to 0.20 g per gram of monomer mixture. In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.005 g to 0.10 g per gram of monomer mixture. In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.005 g to 0.01 g per gram of monomer mixture. In some embodiments, the reaction mixture further comprises an oligomer or polymer in an amount of 0.01 g to 0.05 g per gram of monomer mixture. In some embodiments,

[0148] #14695765vl the reaction mixture further comprises an oligomer or polymer in an amount of 0.05 g to 0.10 g per gram of monomer mixture.

[0149] In some embodiments, co-polymers of (meth)acrylamides and (meth)acrylic acid esters are used in combination with amine-generating blowing agents. Such species may react and turn the copolymer additives into poly(meth)acrylimide during the foaming process. It was found that these homogenizers can, in some instances, prevent phase segregation during polymerization and / or assist and promote the foaming process. The number average molecular weight for these homogenizers can be up to 4 x 106g / mol.

[0150] As described herein, the polymer resin may be impregnated into a plurality of fibers. Referring, for example, to FIGs. 1A-1B, polymer resin 111 is impregnated into plurality of fibers 110 such that polymer resin 111 is between plurality of fibers 110.

[0151] The plurality of fibers (e.g., plurality of fibers 110) may comprise any of a variety of suitable fibers. In some embodiments, the plurality of fibers comprises inorganic fibers and / or organic fibers. In certain embodiments, for example, the plurality of fibers comprises glass fibers, quartz fibers, carbon fibers, aramid fibers, metal fibers, ceramic fibers, mineral fibers, basalt fibers, plastic fibers (e.g., polymer fibers), and / or natural fibers (e.g. bio-fibers). Suitable natural fibers include cotton fibers, cellulose fibers, and / or wool fibers, in accordance with certain embodiments. According to some embodiments, the plurality of fibers are semicrystalline. In certain embodiments, the plurality of fibers are crystalline. In accordance with certain embodiments, the particular fiber type may be selected based on desired mechanical properties, thermal stability, optical characteristics, environmental durability, and / or compatibility with a polymer resin.

[0152] In certain embodiments, the plurality of fibers (e.g., glass fibers and / or natural fibers) are at least partially transparent to actinic radiation (e.g., electromagnetic radiation), which may advantageously facilitate penetration of the actinic radiation through a composite structure comprising the plurality of fibers. In some embodiments, the plurality of fibers are at least partially transparent to at least one wavelength of NIR electromagnetic radiation. In some embodiments, the plurality of fibers have a transparency to at least one wavelength of NIR electromagnetic radiation of at least 1%, at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, or more. In some embodiments, the plurality of fibers have a transparency to at least one wavelength of NIR electromagnetic radiation of less than or equal to 50%, less than or equal to 40%, less than or equal to 30%, less than or equal to 20%, less than or equal to 10%, or less than or equal to 5%. Combinations of the above recited ranges are possible (e.g., the plurality of

[0153] #14695765vl fibers have a transparency to at least one wavelength of NIR electromagnetic radiation of greater than or equal to 1% and less than 50%). Other ranges are also possible.

[0154] According to some embodiments, the transparency of the plurality of fibers (e.g., to at least one wavelength of NIR electromagnetic radiation) is determined by UV-VIS-NIR spectrophotometry.

[0155] In some embodiments, the plurality of fibers (e.g., plurality of fibers 110) may comprise intra-fiber and / or inter-fiber pores. In some embodiments, the presence of intra-fiber and / or inter- fiber pores may advantageously allow the polymer resin to impregnate into the plurality of fibers.

[0156] The plurality of fibers (e.g., plurality of fibers 110) may have any of a variety of suitable dimensions. In certain embodiments, for example, the plurality of fibers comprise microscale fibers (e.g., microfibers) and / or nano sc ale-fibers (e.g., nanofibers). In some embodiments, microscale fibers (e.g., microfibers) have a maximum cross-sectional dimension (e.g., a diameter) greater than or equal to 1 micrometer and less than 500 micrometers. In some embodiments, nanoscale fibers (e.g., nanofibers) have a maximum cross-sectional dimension (e.g., a diameter) greater than or equal to 1 nm and less than 1 micrometer.

[0157] The plurality of fibers (e.g., plurality of fibers 110) may have any of a variety of suitable fiber lengths. In some embodiments, for example, the plurality of fibers have a fiber length greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 5 nm, greater than or equal to 10 nm, greater than or equal to 50 nm, greater than or equal to 100 nm, greater than or equal to 500 nm, greater than or equal to 1 micrometer, greater than or equal to 2 micrometers, greater than or equal to 5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 20 micrometers, greater than or equal to 50 micrometers, greater than or equal to 100 micrometers, greater than or equal to 200 micrometers, greater than or equal to 500 micrometers, greater than or equal 1 mm, greater than or equal to 2 mm, greater than or equal to 5 mm, greater than or equal to 10 mm, greater than or equal to 20 mm, greater than or equal to 50 mm, or greater. In certain embodiments, the plurality of fibers have a fiber length less than or equal to 100 mm, less than or equal to 50 mm, less than or equal to 20 mm, less than or equal to 10 mm, less than or equal to 5 mm, less than or equal to 2 mm, less than or equal to 1 mm, less than or equal to 500 micrometers, less than or equal to 200 micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, less than or equal to 20 micrometers, less than or equal to 10 micrometers, less than or equal to 5 micrometers, less than or equal to 2 micrometers, less than or equal to 1 micrometer, less than or equal to 500 nm, less than or equal

[0158] #14695765vl to 100 nm, less than or equal to 50 nm, less than or equal to 10 nm, less than or equal to 5 nm, or less. Combinations of the above recited ranges are possible (e.g., the plurality of fibers have fiber length greater than or equal to 1 nm and less than or equal to 10 mm). Other ranges are also possible.

[0159] The plurality of fibers (e.g., plurality of fibers 100) may have any of a variety of suitable aspect ratios. As used herein, the aspect ratio of a fiber refers to the average fiber length divided by the average fiber diameter. In certain embodiments, the plurality of fibers have an aspect ratio greater than or equal to 10, greater than or equal to 100, greater than or equal to 500, greater than or equal to 1000, greater than or equal to 1500, greater than or equal to 2000, or more. In some embodiments, the plurality of fibers have an aspect ratio less than or equal to 5000, less than or equal to 2000, less than or equal to 1500, less than or equal to 1000, less than or equal to 500, or less than or equal to 100. Combinations of the above recited ranges are possible (e.g., the plurality of fibers have an aspect ratio greater than or equal to 10 and less than or equal to 5000). Other ranges are also possible. In certain non-limiting embodiments, the plurality of fibers have an aspect ratio of at least 1000.

[0160] According to some embodiments, the plurality of fibers (e.g., plurality of fibers 110) comprise chopped fibers, milled fibers, short fibers, and / or staple fibers.

[0161] The plurality of fibers (e.g., plurality of fibers 110) may be arranged in any of a variety of suitable configurations. In certain embodiments, at least a portion of the plurality of fibers are arranged in an ordered orientation (e.g., unidirectional). In some embodiments, at least a portion (or all) of the fibers are arranged in a random orientation.

[0162] In some embodiments, the plurality of fibers may be in the form of a layer, such as a sheet, mat, or cloth. Referring, for example, to FIGs. 1A-1B, article 101a comprises a plurality of fibers in the form of layer 114 (e.g., a sheet, mat, or cloth). In some embodiments, the layer (e.g., sheet, mat, or cloth) is woven, non-woven, knitted, braided, and / or stitched.

[0163] In some embodiments, a plurality of layers (e.g., a plurality of sheets, mats, or cloths) may be stacked to form a layered configuration of the plurality of fibers. FIG. 1C shows, according to certain embodiments, a cross-sectional schematic diagram of article 101b comprising a plurality of layers 114 (e.g., layers 114a- 114c).

[0164] In certain embodiments, the polymer resin may impregnate into the plurality of fibers of each layer. Referring, for example, to FIG. 1C, polymer resin 111 impregnated into plurality of fibers 110 of each layer 114 (e.g., layers 114a-114c).

[0165] #14695765vl According to some embodiments, the polymer resin forms a continuous phase across a boundary of the layers. For example, referring to FIG. 1C, polymer resin 111 forms a continuous phase across boundary 116’ (of layers 114a and 114b) and boundary 116” (of layers 114b and 114c). It is also possible for an article to comprise two or more layers that are each impregnated with a polymer resin, but for which the polymer resin does not form a continuous phase across the boundary therebetween.

[0166] The polymer resin may be impregnated into the plurality of fibers via any of a variety of suitable methods. In some embodiments, the polymer resin is impregnated into the plurality of fibers via a dry processing technique. In certain embodiments, the polymer resin is impregnated into the plurality of fibers via wet processing technique.

[0167] In certain embodiments, the method comprises performing a hand lay-up process, a resin transfer molding process, a vacuum assisted resin transfer molding process, a filament winding process, braiding, a liquid molding process, a liquid compression molding process, a high- pressure resin transfer molding process, pultrusion, a tape deposition process, ribbonizing, an additive manufacturing process, a compression molding process, and / or a sheet molding compounding process to produce the fiber-reinforced composite. Other methods of impregnating the plurality of fibers with the polymer resin are also possible.

[0168] According to some embodiments, the method of impregnating the polymer resin into the plurality of fibers may depend on the viscosity of the polymer resin. In certain embodiments, for example, a polymer resin having a viscosity greater than or equal to 150 cPs and less than or equal to 1000 cPs at 25 °C is suitable for filament winding. In some embodiments, a polymer resin having a viscosity greater than or equal to 10 cPs and less than or equal to 100 cPs at 25 °C is suitable for a high-pressure resin transfer molding process In some embodiments, a polymer resin having a viscosity greater than or equal to 500 cPs and less than or equal to 1500 cPs at 25 °C is suitable for hand lay-up process. Other combinations of polymer viscosities and / or impregnating methods are also possible.

[0169] In certain embodiments, the method comprises curing the polymer resin to form a precursor polymer or a polymer. According to some embodiments, curing the polymer resin comprises exposing the polymer resin to actinic radiation. The actinic radiation may, in some embodiments, comprise electromagnetic radiation. In certain embodiments, the actinic radiation comprises UV, visible, and / or IR electromagnetic radiation. In some embodiments, the polymer resin may comprise a photoinitiator, such as any of the photoinitiators described herein.

[0170] #14695765vl In certain embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 100 nm, greater than or equal to 200 nm, greater than or equal to 300 nm, greater than or equal to 400 nm, greater than or equal to 500 nm, greater than or equal to 600 nm, greater than or equal to 700 nm, greater than or equal to 800 nm, greater than or equal to 900 nm, greater than or equal to 1 micrometer, greater than or equal to 1.1 micrometers, greater than or equal to 1.2 micrometers, greater than or equal to 1.3 micrometers, greater than or equal to 1.4 micrometers, greater than or equal to 1.5 micrometers, greater than or equal to 2 micrometers, greater than or equal to 3 micrometers, greater than or equal to 5 micrometers, greater than or equal to 10 micrometers, or greater than or equal to 50 micrometers. In some embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 1 mm, less than or equal to 50 micrometers, less than or equal to 10 micrometers, less than or equal to 5 micrometers, less than or equal to 3 micrometers, less than or equal to 2 micrometers, less than or equal to 1.5 micrometers, less than or equal to 1.4 micrometers, less than or equal to 1.3 micrometers, less than or equal to 1.2 micrometers, less than or equal to 1.1 micrometers, less than or equal to 1 micrometer, less than or equal to 900 nm, less than or equal to 800 nm, less than or equal to 700 nm, less than or equal to 600 nm, less than or equal to 500 nm, less than or equal to 400 nm, or less than or equal to 300 nm, less than or equal to 200 nm. Combinations of the above recited ranges are possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 100 nm and less than or equal to 1 mm). Other ranges are also possible.

[0171] In some embodiments, the actinic radiation comprises UV electromagnetic radiation. In some embodiments, for example, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 100 nm, greater than or equal to 200 nm, or greater than or equal to 300 nm. In some embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 400 nm, less than or equal to 300 nm, or less than or equal to 200 nm. Combinations of the above recited ranges are possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 100 nm and less than or equal to 400 nm). Other ranges are also possible.

[0172] In certain embodiments, the actinic radiation comprises short wavelength UV electromagnetic radiation (e.g., UV-C and / or UV-B electromagnetic radiation). In some embodiments, for example, the actinic radiation comprises electromagnetic radiation having a wavelength greater than or equal to 100 nm, greater than or equal to 200 nm, or greater than or

[0173] #14695765vl equal to 280 nm. In some embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 315 nm, less than or equal to 300 nm, less than or equal to 280 nm, or less than or equal to 200 nm. Combinations of the above recited ranges are possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 100 nm and less than or equal to 280 nm, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 280 nm and less than or equal to 315 nm). Other ranges are also possible.

[0174] According to some embodiments, the polymer resin does not include a photoinitiator when exposed to electromagnetic radiation having a wavelength less than 200 nm.

[0175] In some embodiments, the actinic radiation comprises longwave UV electromagnetic radiation (e.g., UV-A electromagnetic radiation). In certain embodiments, for example, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 315 nm or greater than or equal to 350 nm. In some embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 400 nm or less than or equal to 350 nm. Combinations of the above recited ranges are also possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 315 nm and less than or equal to 400 nm). Other ranges are also possible.

[0176] In certain embodiments, the actinic radiation comprises visible electromagnetic radiation. In some embodiments, for example, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 400 nm, greater than or equal to 500 nm, or greater than or equal to 600 nm. In certain embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 700 nm, less than or equal to 600 nm, or less than or equal to 500 nm. Combinations of the above recited ranges are possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 400 nm and less than or equal to 700 nm). Other ranges are also possible.

[0177] According to some embodiments, the actinic radiation comprises IR electromagnetic radiation. For example, in certain embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of greater than or equal to 700 nm, greater than or equal to 800 nm, greater than or equal to 900 nm, greater than or equal to 1 micrometer, greater than or equal to 1.1 micrometers, greater than or equal to 1.2 micrometers, greater than or equal to 1.3 micrometers, greater than or equal to 1.4 micrometers, greater than or equal to 1.5 micrometers, greater than or equal to 2 micrometers, greater than or equal to 3 micrometers, greater than or

[0178] #14695765vl equal to 5 micrometers, greater than or equal to 10 micrometers, or greater than or equal to 50 micrometers. In some embodiments, the actinic radiation comprises electromagnetic radiation having a wavelength of less than or equal to 1 mm, less than or equal to 50 micrometers, less than or equal to 10 micrometers, less than or equal to 5 micrometers, less than or equal to 3 micrometers, less than or equal to 2 micrometers, less than or equal to 1.5 micrometers, less than or equal to 1.4 micrometers, less than or equal to 1.3 micrometers, less than or equal to 1.2 micrometers, less than or equal to 1.1 micrometers, less than or equal to 1 micrometer, less than or equal to 900 nm, or less than or equal to 800 nm. Combinations of the above recited ranges are possible (e.g., the actinic radiation comprises electromagnetic radiation having a wavelength greater than or equal to 700 nm and less than or equal to 1 mm). Other ranges are also possible.

[0179] In certain embodiments, curing the polymer resin comprises irradiating the polymer resin with NIR electromagnetic radiation. In some embodiments, the polymer resin may comprise a NIR dye, such as any of the NIR dyes described herein. In certain embodiments, the polymer resin may comprise a photothermal agent, such as any of the photothermal agents described herein.

[0180] In certain non-limiting embodiments, the plurality of fibers comprises carbon fibers and curing the polymer resin comprises irradiating the polymer resin and / or the carbon fibers with IR (e.g., NIR) radiation. In certain embodiments, irradiation of the carbon fibers causes the carbon fibers to generate heat that causes curing of the polymer resin via a photothermal effect. In some embodiments, for example, upon absorption of NIR electromagnetic radiation, the carbon fibers advantageously generate heat that may activate one or more thermal initiators. In certain embodiments, the polymer resin does not include a NIR dye and / or a photo thermal agent when the plurality of fibers comprise carbon fibers and the polymer resin is irradiated with IR (e.g., NIR) radiation.

[0181] In some embodiments, curing the polymer resin comprises irradiating the polymer resin with NIR electromagnetic radiation having a wavelength of greater than or equal to 700 nm, greater than or equal to 800 nm, greater than or equal to 900 nm, greater than or equal to 1 micrometer, greater than or equal to 1.1 micrometers, greater than or equal to 1.2 micrometers, or greater than or equal to 1.3 micrometers. In some embodiments, curing the polymer resin comprises irradiating the polymer resin with NIR electromagnetic radiation having a wavelength of less than or equal to 1.4 micrometers, less than or equal to 1.3 micrometers, less than or equal to 1.2 micrometers, less than or equal to 1.1 micrometers, less than or equal to 1 micrometer, less than or equal to 900 nm, or less than or equal to 800 nm. Combinations of the above recited

[0182] #14695765vl ranges are possible (e.g., curing the polymer resin comprises irradiating the polymer resin with NIR electromagnetic radiation having a wavelength of greater than or equal to 700 nm and less than or equal to 1.4 micrometers). Other ranges are also possible.

[0183] According to some embodiments, the actinic radiation comprises electron beam radiation.

[0184] In certain embodiments, the polymer resin does not include a photoinitiator when exposed to electron beam radiation.

[0185] In some embodiments, the actinic radiation does not comprise gamma radiation.

[0186] The polymer resin may be exposed to actinic radiation for any of a variety of suitable durations. In some embodiments, for example, the polymer resin is exposed to actinic radiation for greater than or equal to 0.1 seconds, greater than or equal to 0.5 seconds, greater than or equal to 1 second, greater than or equal to 5 seconds, greater than or equal to 10 seconds, greater than or equal to 30 seconds, greater than or equal to 1 minute, greater than or equal to 2 minutes, greater than or equal to 5 minutes, greater than or equal to 10 minutes, greater than or equal to 30 minutes, greater than or equal to 1 hour, greater than or equal to 2 hours, greater than or equal to 3 hours, greater than or equal to 5 hours, greater than or equal to 10 hours, greater than or equal to 20 hours, greater than or equal to 40 hours, greater than or equal to 60 hours, or greater than or equal to 80 hours. In some embodiments, the polymer resin is exposed to actinic radiation for less than or equal to 100 hours, less than or equal to 80 hours, less than or equal to 60 hours, less than or equal to 40 hours, less than or equal to 20 hours, less than or equal to 3 hours, less than or equal to 2 hours, less than or equal to 1 hour, less than or equal to 30 minutes, less than or equal to 10 minutes, less than or equal to 5 minutes, less than or equal to 2 minutes, less than or equal to 1 minute, less than or equal to 30 seconds, less than or equal to 10 seconds, less than or equal to 5 seconds, less than or equal to 1 second, or less than or equal to 0.5 seconds. Combinations of the above recited ranges are possible (e.g., the polymer resin is exposed to actinic radiation for greater than or equal to 0.1 seconds and less than or equal to 100 hours). Other ranges are also possible.

[0187] In some embodiments, curing the polymer resin comprises heating the polymer resin. In some embodiments, the polymer resin may comprise a thermal initiator, such as any of the thermal initiators described herein.

[0188] The polymer resin may be heated via any of a variety of suitable mechanisms. In certain embodiments, the polymer resin is heated via exposure to radiation (e.g., electromagnetic radiation). In some embodiments, the polymer resin is heated via exposure to convection

[0189] #14695765vl heating, conduction heating, induction heating, resistance heating, and / or ultrasonic heating. Other mechanisms and / or sources of heat are also possible.

[0190] The polymer resin may be heated to any of a variety of suitable temperatures. In some embodiments, for example, the polymer resin is heated to a temperature greater than or equal to 25 °C, greater than or equal to 50 °C, greater than or equal to 100 °C, greater than or equal to 125 °C, greater than or equal to 150 °C, greater than or equal to 175 °C, greater than or equal to 200 °C, greater than or equal to 225 °C, greater than or equal to 250 °C, or greater than or equal to 275 °C. In certain embodiments, the polymer resin is heated to a temperature less than or equal to 300 °C, less than or equal to 275 °C, less than or equal to 250 °C, less than or equal to 225 °C, less than or equal to 200 °C, less than or equal to 175 °C, less than or equal to 150 °C, less than or equal to 125 °C, less than or equal to 100 °C, less than or equal to 75 °C, or less than or equal to 50 °C. Combinations of the above recited ranges are possible (e.g., the polymer resin is heated to a temperature greater than or equal to 25 °C and less than or equal to 300 °C). Other ranges are also possible.

[0191] The polymer resin may be heated for any of a variety of suitable durations. In some embodiments, for example, the polymer resin is heated for greater than or equal to 1 second, greater than or equal to 30 seconds, greater than or equal to 1 minute, greater than or equal to 2 minutes, greater than or equal to 5 minutes, greater than or equal to 10 minutes, greater than or equal to 30 minutes, greater than or equal to 1 hour, greater than or equal to 2 hours, greater than or equal to 3 hours, greater than or equal to 4 hours, greater than or equal to 5 hours, greater than or equal to 10 hours, greater than or equal to 20 hours, greater than or equal to 40 hours, greater than or equal to 60 hours, or greater than or equal to 80 hours. In some embodiments, the polymer resin is heated for less than or equal to 100 hours, less than or equal to 80 hours, less than or equal to 60 hours, less than or equal to 40 hours, less than or equal to 20 hours, less than or equal to 10 hours, less than or equal to 5 hours, less than or equal to 4 hours, less than or equal to 3 hours, less than or equal to 2 hours, less than or equal to 1 hour, less than or equal to 30 minutes, less than or equal to 10 minutes, less than or equal to 5 minutes, less than or equal to 2 minutes, less than or equal to 1 minute, or less than or equal to 30 seconds. Combinations of the above recited ranges are possible (e.g., the polymer resin is heated for greater than or equal to 1 second and less than or equal to 100 hours). Other ranges are also possible.

[0192] In certain embodiments, curing the polymer resin comprises a temperature ramping process in which the temperature of the polymer resin is increased over time. The duration of

[0193] #14695765vl the temperature ramping process may be the duration described above suitable for heating the polymer resin (e.g., greater than or equal to 1 second and less than or equal to 100 hours).

[0194] According to certain embodiments, curing the polymer resin comprises exposing the polymer resin to actinic radiation and heating the polymer resin (e.g., concurrently).

[0195] In some embodiments, exposing the polymer resin to actinic radiation comprising IR electromagnetic radiation may advantageously cure the polymer resin: (i) thermally (e.g., via activation of a thermal initiator by a photothermal effect generated by the IR electromagnetic radiation); and (ii) photochemically (e.g., via activation of a photoinitiator).

[0196] In some embodiments, exposing the polymer resin to actinic radiation comprising NIR electromagnetic radiation may advantageously cure the polymer resin: (i) thermally (e.g., via activation of a thermal initiator by a photothermal effect generated by the NIR electromagnetic radiation); and (ii) photochemically (e.g., via activation of a photoinitiator). In certain embodiments, wherein the polymer resin comprises a NIR dye, a salt initiator, and optionally a reducing agent, exposing the polymer resin to actinic radiation comprising NIR electromagnetic radiation may advantageously cure the polymer resin: (i) thermally (e.g., via activation of a thermal initiator by a photo thermal effect generated by the NIR electromagnetic radiation); and (ii) photochemically via a photoredox system using the NIR dye as a sensitizer together with the salt initiator (and optionally the reducing agent to restore the catalytic cycle). In some embodiments, wherein the polymer resin comprises a NIR dye, a salt initiator, and optionally a reducing agent, exposing the polymer resin to actinic radiation comprising NIR electromagnetic radiation may advantageously cure the polymer resin: (i) thermally (e.g., via activation of a thermal initiator by a photo thermal effect generated by the NIR electromagnetic radiation); (ii) photochemically (e.g., via activation of a photoinitiator); and (iii) photochemically via a photoredox system using the NIR dye as a sensitizer together with the salt initiator (and optionally the reducing agent to restore the catalytic cycle).

[0197] In some embodiments, curing the polymer resin comprises performing partial curing (e.g., B-stage curing). For example, in some embodiments, the polymer resin is partially cured with actinic radiation and / or heat radiation to form a precursor polymer that is partially solid and / or tacky. In some embodiments, the at least partially cured precursor polymer may advantageously ease shaping of the precursor polymer and / or the final (e.g., fully cured) product. In certain embodiments, for example, the at least partially cured precursor polymer may be postprocessed or post-formed to a desired shape (e.g., and, subsequently, fully cured). In some embodiments, B-stage curing occurs after impregnating the polymer resin into the plurality of

[0198] #14695765vl fibers. In certain embodiments, B-stage curing occurs before impregnating the polymer resin into the plurality of fibers.

[0199] According to some embodiments, curing the polymer resin comprises complete curing (e.g., C-stage curing). In some embodiments, for example, the polymer resin is fully cured with actinic radiation and / or heat to form a solid polymer. In some embodiments, the polymer resin is fully cured (e.g., via C-stage curing) after partially curing (e.g., B-stage curing). It is also possible for a polymer resin to comprise one or more portions that are partially cured and one or more portions that are fully cured. Such polymer resins may be particularly suitable for applications in which it is desirable for different portions to have different mechanical properties, as the partially cured portions may be more flexible than the fully cured portions.

[0200] In certain embodiments, curing the polymer resin comprises at least partially imidizing the precursor polymer. In some embodiments, for example, curing the polymer resin and imidizing the precursor polymer occur concurrently, without the need for a separate, subsequent imidization step.

[0201] In some embodiments, curing the polymer resin comprises gel coat curing. In certain embodiments, for example, a topcoat or gel coat layer of the polymer resin is cured with actinic radiation and / or heat after applying the topcoat or gel coat layer to a fully cured polymer impregnated within a plurality of fibers. The cured topcoat or gel coat layer may advantageously provide scratch-resistance and / or durability.

[0202] As described herein, curing the polymer resin (e.g., comprising a monomer, comonomer, and / or oligomer) may form a precursor polymer or a polymer. The precursor polymer may be any of a variety of suitable precursors. In some embodiments, for example, the precursor polymer is a precursor to a poly(meth)acrylimide, an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, a bismaleimide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylenesulfide, a polyether ketone, a polyether imide, a polystyrene, a vinyl ether, a lactone, a blend of two or more of the foregoing, and / or a copolymer of two or more of the foregoing. Other polymers are also possible. In some embodiments, the polymer resin and / or the precursor polymer further comprises a precursor to a polyacrylate and / or a polymethacrylate.

[0203] In certain embodiments, a polymer resin comprising a precursor to an epoxy, a phenolic resin, a polyester, a polyurethane, a bismalemide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylsulfide, a polyether ketone, and / or a polyether imide may be cured by exposing the polymer resin comprising a NIR dye to actinic radiation comprising NIR

[0204] #14695765vl electromagnetic radiation without including an initiator. In some embodiments, a polymer resin comprising a precursor to a polyacrylate, a polymethacrylate, a polystyrene, a styrene acrylonitrile, a polyester, and / or a vinyl ester may be cured by exposing the polymer resin comprising a NIR dye and a thermal initiator to actinic radiation comprising NIR electromagnetic radiation. In certain embodiments, a polymer resin comprising a precursor to a polymethyacrylate, a polyacrylate, a polystyrene, a styrene acrylonitrile, a polyester, a vinyl ether, a vinyl ester, an epoxy, and / or a lactone may be cured by exposing the polymer resin comprising a NIR dye and a photoinitiator to actinic radiation comprising NIR electromagnetic radiation.

[0205] In some embodiments, a precursor polymer comprises an optionally substituted polyacrylic ester, an optionally substituted polyacrylamide, an optionally substituted polyacrylic acid, an optionally substituted polyacrylonitrile, and / or any copolymer thereof. In some embodiments, a precursor polymer comprises an optionally substituted polyacrylic ester, an optionally substituted polyacrylamide, an optionally substituted polyacrylic acid, and / or any copolymer thereof. In some embodiments, a precursor polymer comprises an optionally substituted poly(meth)acrylic ester, an optionally substituted poly(meth)acrylamide, an optionally substituted poly(meth)acrylic acid, and / or any copolymer thereof. In some embodiments, a precursor polymer comprises an optionally substituted polyacrylic ester, an optionally substituted polyacrylamide, an optionally substituted polyacrylic acid, an optionally substituted polyacrylonitrile, and / or any copolymer thereof prepared according to a method provided herein.

[0206] The precursor polymer may have any of a variety of suitable viscosities (e.g., dynamic viscosities). In some embodiments, the viscosity of the precursor polymer is greater than the viscosity of the polymer resin prior to curing. In certain embodiments, for example, the precursor polymer has a viscosity of at least 50 cPs, at least 90 cPs, at least 100 cPs, at least 200 cPs, at least 300 cPs, at least 400 cPs, at least 500 cPs, at least 600 cPs, at least 700 cPs, at least 800 cPs, at least 900 cPs, at least 1,000 cPs, at least 1,100 cPs, at least 1,200 cPs, at least 1,300 cPs, at least 1,500 cPs, at least 2,000 cPs, at least 3,000 cPs, at least 4,000 cPs, at least 5,000 cPs, at least 10,000 cPs, at least 20,000 cPs, at least 30,000 cPs, at least 40,000 cPs, at least 50,000 cPs, at least 100,000 cPs, at least 200,000 cPs, at least 500,000 cPs, or greater, at 25 °C. In some embodiments, the precursor polymer has a viscosity of less than or equal 1,000,000 cPs, less than or equal 500,000 cPs, less than or equal to 200,000 cPs, less than or equal to 100,000 cPs, less than or equal to 50,000 cPs, less than or equal to 40,000 cPs, less than or equal to 30,000

[0207] #14695765vl cPs, less than or equal to 20,000 cPs, less than or equal to 10,000 cPs, less than or equal to 5,000 cPs, less than or equal to 4,000 cPs, less than or equal to 3,000 cPs, less than or equal to 2,000 cPs, less than or equal to 1,500 cPs, less than or equal to 1,400 cPs, less than or equal to 1,300 cPs, less than or equal to 1,200 cPs, less than or equal to 1,100 cPs, less than or equal to 1000 cPs, less than or equal to 900 cPs, less than or equal to 800 cPs, less than or equal to 700 cPs, less than or equal to 600 cPs, less than or equal to 500 cPs, less than or equal to 400 cPs, less than or equal to 300 cPs, less than or equal to 200 cPs, less than or equal to 100 cPs, or less than or equal to 90 cPs at 25 °C. Combinations of the above recited ranges are possible (e.g., the precursor polymer has a viscosity of at least 50 cPs and less than or equal to 200,000 cPs at 25 °C). Other ranges are also possible.

[0208] In certain embodiments, the viscosity of the precursor polymer is measured by ASTM D2196 (2020) at 25 °C using a rotational viscometer.

[0209] According to some embodiments, the method comprises imidizing the precursor polymer to form a poly(meth)acrylimide. The term “poly(meth)acrylimide” as used herein describes both polymethacrylimides and poly aery limides. In some embodiments, a poly(meth)acrylimide comprises a polymethacrylimide and / or a poly aery limide. In some embodiments, a poly(meth)acrylimide is a polymethacrylimide. In some embodiments a poly(meth)acrylimide is a polyacrylimide. In some embodiments, the poly(meth)acrylimide is optionally substituted.

[0210] According to some embodiments, the poly(meth)acrylimide after imidization contains repeat units according to formula (I): wherein:

[0211] Ri and R2 are the same or different and are each a hydrogen (acrylate) or methyl group (methacrylate),

[0212] R3 is hydrogen, optionally substituted acyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted heteroalkyl, optionally substituted heteroalkenyl, optionally substituted heteroalkynyl, optionally substituted

[0213] #14695765vl carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, or a nitrogen protecting group.

[0214] In some embodiments, in at least one repeat unit, Ri and R2 are each methyl. In some embodiments, in at least one repeat unit, Ri and R2 are each hydrogen. In some embodiments, in at least one repeat unit, one of Ri and R2 is hydrogen and the other is methyl. In some embodiments, in at least one repeat unit, Ri is hydrogen and R2 is methyl. In some embodiments, in at least one repeat unit, Ri is methyl and R2 is hydrogen.

[0215] In some embodiments, R3 is a hydrogen or optionally substituted alkyl, or optionally substituted aryl having up to 36 carbon atoms, or optionally substituted aliphatic, or optionally substituted heteroaliphatic, or optionally substituted aryl, or optionally substituted heteroaryl (and possibly even also optionally substituted carbocyclyl and optionally substituted heterocyclyl), which may additionally contain oxygen, nitrogen, sulphur and / or phosphorous atoms in the form of typical organic functionalities, such as for example, an ether, alcohol, acid, ester, amide, imide, phosphonic acid, phosphonic ester, phosphoric acid, phosphoric ester, phosphinic acid, phosphinic ester, sulphonic acid, sulphonic ester, sulphinic acid and / or sulphinic ester function, silicon, aluminium and boron atoms and / or halogens, such as fluorine, chlorine, bromine and / or iodine.

[0216] In some embodiments, in at least one repeat unit, R? is hydrogen, optionally substituted alkyl, or a nitrogen protecting group. In some embodiments, in at least one repeat unit, R3 is hydrogen or a nitrogen protecting group. In some embodiments, in at least one repeat unit, R3 is hydrogen. In some embodiments, in at least one repeat unit, R3 is a nitrogen protecting group.

[0217] In some embodiments, in at least one repeat unit, R3 is optionally substituted acyl.

[0218] In some embodiments, in at least one repeat unit, R3 is hydrogen or optionally substituted alkyl. In some embodiments, in at least one repeat unit, R3 is hydrogen or optionally substituted C1-C36 alkyl. In some embodiments, in at least one repeat unit, R3 is hydrogen or optionally substituted C1-C20 alkyl. In some embodiments, in at least one repeat unit, R3 is hydrogen or optionally substituted Ci-Cs alkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted alkyl, optionally substituted alkenyl, or optionally substituted alkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted alkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C36 alkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C20 alkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs alkyl. The following may be mentioned as examples of R3, without being restricted to thereto: methyl, ethyl, propyl,

[0219] #14695765vl 2-propyl, butyl, tert-butyl, hexyl, ethylhexyl, octyl, dodecyl, octadecyl. In some embodiments, in at least one repeat unit, R3 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t-butyl optionally substituted with hydroxy or alkoxy. In some embodiments, in at least one repeat unit, R3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, or t- butyl. In some embodiments, R3 is hydrogen, methyl, 2-hydroxyethyl, or isopropyl. In some embodiments, R3 is methyl. In some embodiments, R3 is 2-hydroxyethyl. In some embodiments, R3 is isopropyl.

[0220] In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C36 alkenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C20 alkenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs alkenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C36 alkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C20 alkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs alkynyl.

[0221] In some embodiments, in at least one repeat unit, R3 is optionally substituted heteroalkyl, optionally substituted heteroalkenyl, or optionally substituted heteroalkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted heteroalkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C36 heteroalkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C20 heteroalkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs heteroalkyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C36 heteroalkenyl. In some embodiments, in at least one repeat unit, Rds optionally substituted C1-C20 heteroalkenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs heteroalkenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci- C36 heteroalkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C1-C20 heteroalkynyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ci-Cs heteroalkynyl.

[0222] In some embodiments, in at least one repeat unit, R3 is optionally substituted carbocyclyl or optionally substituted heterocyclyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted carbocyclyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C3-C8 carbocyclyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted C5-C6 carbocyclyl. In some embodiments, in at least one repeat unit, R3 is

[0223] #14695765vl -M - optionally substituted heterocyclyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted 3- to 8-membered heterocyclyl.

[0224] In some embodiments, in at least one repeat unit, R3 is optionally substituted aryl or optionally substituted heteroaryl. In some embodiments, in at least one repeat unit, R3 is optionally substituted aryl. In some embodiments, in at least one repeat unit, R3 is optionally substituted Ce-Cio aryl. In some embodiments, in at least one repeat unit, R3 is optionally substituted phenyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted heteroaryl. In some embodiments, in at least one repeat unit, R3 is optionally substituted 5- to 10-membered heterocyclyl. In some embodiments, in at least one repeat unit, R3 is optionally substituted 5- to 6-membered heterocyclyl.

[0225] In some embodiments, imidizing the precursor polymer comprises irradiating the polymer resin with actinic radiation. In certain embodiments, the actinic radiation comprises electromagnetic radiation, as described herein in greater detail. In some embodiments, imidizing the precursor polymer comprises irradiating the polymer resin with actinic radiation having a wavelength and for a duration as described elsewhere herein, such as a wavelength of actinic radiation and a duration suitable for curing the polymer resin.

[0226] According to certain embodiments, imidizing the precursor polymer comprises irradiating the polymer resin with IR electromagnetic radiation. In some embodiments, imidizing the precursor polymer comprises imidizing the polymer resin with NIR electromagnetic radiation. In certain embodiments, the plurality of fibers comprises carbon fibers and imidizing the precursor polymer comprises irradiating the polymer resin and / or the carbon fibers with IR (e.g., NIR) electromagnetic radiation. In certain embodiments, irradiation of the carbon fibers causes the carbon fibers to generate heat that causes imidization of the precursor polymer via a photothermal effect. In some embodiments, for example, upon absorption of NIR electromagnetic radiation, the carbon fibers advantageously generate heat that may activate one or more thermal initiators. In certain embodiments, the polymer resin does not include a NIR dye and / or a photothermal agent when the plurality of fibers comprise carbon fibers and the polymer resin is irradiated with IR (e.g., NIR) electromagnetic radiation to imidize the precursor polymer.

[0227] In certain embodiments, a fiber-reinforced composite comprises a precursor polymer to a poly(meth)acrylimide, a photo thermal agent, and a plurality of fibers. In certain embodiments, for example, the photothermal agent is dispersed within the precursor polymer, which is impregnated within the plurality of fibers. In certain embodiments, imidizing the precursor

[0228] #14695765vl polymer comprises irradiating the fiber-reinforced composite with NIR and / or IR electromagnetic radiation.

[0229] In certain embodiments, imidizing the precursor polymer comprises heating the polymer resin. In some embodiments, imidizing the precursor polymer comprises heating the polymer resin to a temperature and for a duration as described elsewhere herein, such as a temperature and a duration suitable for curing the polymer resin. In some embodiments, the heating causes the precursor polymer to undergo foaming. In some embodiments, the foaming step comprises heating the precursor polymer. In some embodiments, the foaming step comprises heating the precursor polymer below the Tgof the precursor polymer. In some embodiments, the heat is supplied using conduction, convection, or radiation. In some embodiments, the heat is supplied using a hot-air convection furnace, microwave radiation, magnetic induction, infrared radiation, and / or near-infrared radiation. In some embodiments, the heat is supplied using a furnace, heating element, or water bath. In some embodiments, the heat is supplied using a hot-air convection furnace.

[0230] In some embodiments, imidizing the precursor polymer occurs concurrently with curing the polymer resin (e.g., as a part of the same exposure to actinic radiation and / or heat). In certain embodiments, imidizing the precursor polymer occurs after curing the polymer resin to provide the precursor polymer (e.g., as separate exposures to actinic radiation and / or heat).

[0231] According to some embodiments, imidizing the precursor polymer comprises partial imidization.

[0232] In some embodiments, an imidizing step (e.g., imidization) described herein occurs without foaming. In some embodiments, a method provided herein further comprises a step of foaming the precursor polymer. In some embodiments, the imidizing step (e.g., imidization) is performed prior to, concurrent with, or subsequent to the foaming step. In some embodiments, the imidizing step (e.g., imidization) is performed prior to the foaming step. In some embodiments, the imidizing step (e.g., imidization) is performed concurrently with the foaming step. According to some embodiments, imidizing the precursor polymer causes the precursor polymer to undergo foaming. In certain embodiments, imidizing the precursor polymer comprises partial foaming. In some embodiments, the imidizing step (e.g., imidization) is performed subsequent to the foaming step.

[0233] Methods for inducing imidization and foaming include but are not limited to, supplying heat using hot-air convection furnaces, microwave electromagnetic radiation, magnetic

[0234] #14695765vl induction, IR electromagnetic radiation, NIR electromagnetic radiation, optionally combined with one or more NIR dyes, such as those described herein in greater detail.

[0235] In some embodiments, the imidizing step (e.g., imidization) is performed prior to the foaming step using a blowing agent that volatilizes or decomposes above the imidization temperature. In some embodiments, the imidizing step (e.g., imidization) is performed concurrently with the foaming step using a blowing agent that volatilizes or decomposes close to the imdization temperature. In some embodiments, the imidizing step (e.g., imidization) is performed concurrently with the foaming step when a blowing agent is generated during the imidizing step (e.g., imidization). In some embodiments, the heating during the imidizing step causes the precursor polymer to undergo foaming. In some embodiments, the imidizing step (e.g., imidization) is performed subsequent to the foaming step using a blowing agent that volatilizes or decomposes below the imidization temperature.

[0236] In some embodiments, at least a portion of the precursor polymer undergoes imidization. In some embodiments, at least 20% of the precursor polymer undergoes imidization. In some embodiments, at least 40% of the precursor polymer undergoes imidization. In some embodiments, at least 60% of the precursor polymer undergoes imidization. In some embodiments, at least 80% of the precursor polymer undergoes imidization. In some embodiments, at least 90% of the precursor polymer undergoes imidization. In some embodiments, at least 95% of the precursor polymer undergoes imidization. In some embodiments, 20%-100% of the precursor polymer undergoes imidization. In some embodiments, 40%-100% of the precursor polymer undergoes imidization. In some embodiments, 60%-100% of the precursor polymer undergoes imidization. In some embodiments, 80%-100% of the precursor polymer undergoes imidization.

[0237] In some embodiments, the foaming step comprises heating the precursor polymer above the imidization temperature. In some embodiments, the foaming step comprises heating the precursor polymer above 150 °C. In some embodiments, the foaming step comprises heating the precursor polymer above 170 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 150 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 160 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 170 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 180 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 190 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 200 °C to

[0238] #14695765vl 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from

[0239] 150 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 160 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 170 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 180 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 190 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 200 °C to 250 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 150 °C to 200 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 160 °C to

[0240] 200 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 170 °C to 200 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 180 °C to 200 °C. In some embodiments, the foaming step comprises heating the precursor polymer from 190 °C to 200 °C.

[0241] In some embodiments, the foaming step comprises heating the precursor polymer below the imidization temperature. In some embodiments, the foaming step comprises heating the precursor polymer up to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer up to 150 °C. In some embodiments, the foaming step comprises heating the precursor polymer up to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer up to 130 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 30 °C to 160 °C. I n some embodiments, the foaming step comprises heating the precursor polymer to 40 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 50 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 60 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 70 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 80 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 90 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 100 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 110 °C to 160 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 30 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 40 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 50 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 60 °C to 140 °C. In some

[0242] #14695765vl embodiments, the foaming step comprises heating the precursor polymer to 70 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 80 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 90 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 100 °C to 140 °C. In some embodiments, the foaming step comprises heating the precursor polymer to 110 °C to 140 °C.

[0243] According to some embodiments, the methods described herein produce a fiber- reinforced composites.

[0244] FIG. 2 A shows, according to certain embodiments, a schematic diagram of fiber- reinforced composite 102a. The fiber-reinforced composite may have any of a variety of suitable dimensions. In certain embodiments, for example, referring to FIG. 2 A, fiber-reinforced composite 102a comprises first dimension 104 and second dimension 106. According to certain embodiments, second dimension 106 is perpendicular to first dimension 104.

[0245] The length of first dimension 104 may be any of a variety of suitable lengths. In some embodiments, for example, first dimension 104 has a length of at least 1 centimeter, at least 2 centimeters, at least 5 centimeters, at least 10 centimeters, at least 15 centimeters, at least 20 centimeters, at least 50 centimeters, at least 100 centimeters, or more. In certain embodiments, first dimension 104 has a length of less than or equal to 1 meter, less than or equal to 100 centimeters, less than or equal to 50 centimeters, less than or equal to 20 centimeters, less than or equal to 15 centimeters, less than or equal to 10 centimeters, less than or equal to 5 centimeters, or less than or equal to 2 centimeters. Combinations of the above recited ranges are possible (e.g., first dimension 104 has a length of at least 1 centimeter and less than or equal to 1 meter). Other ranges are also possible.

[0246] The length of second dimension 106 may be any of a variety of suitable lengths. In some embodiments, for example, second dimension 106 has a length of at least 1 centimeter, at least 2 centimeters, at least 5 centimeters, at least 10 centimeters, at least 15 centimeters, at least 20 centimeters, at least 50 centimeters, at least 100 centimeters, at least 1 meter, at least 5 meters, or more. In certain embodiments, second dimension 106 has a length of less than or equal to 12 meters, less than or equal to 10 meters, less than or equal to 5 meters, less than or equal to 1 meter, less than or equal to 100 centimeters, less than or equal to 50 centimeters, less than or equal to 20 centimeters, less than or equal to 15 centimeters, less than or equal to 10 centimeters, less than or equal to 5 centimeters, or less than or equal to 2 centimeters. Combinations of the

[0247] #14695765vl above recited ranges are possible (e.g., second dimension 106 has a length of at least 1 centimeter and less than or equal to 12 meters). Other ranges are also possible.

[0248] According to certain embodiments, fiber-reinforced composite 102a comprises third dimension 108. In some embodiments, third dimension 108 is perpendicular to first dimension 104 and second dimension 106. In some embodiments, third dimension 108 is a thickness of fiber-reinforced composite 102a.

[0249] The length of the third dimension may be any of a variety of suitable lengths. In certain embodiments, the length of third dimension 108 is advantageously thin. In some embodiments, for example, third dimension 108 has a length of less than or equal to 50 centimeters, less than or equal to 10 centimeters, less than or equal to 5 centimeters, less than or equal to 1 centimeter, less than or equal to 0.5 centimeters, less than or equal to 0.1 centimeters, less than or equal to 500 micrometers, less than or equal to 100 micrometers, or less than or equal to 50 micrometers. In some embodiments, third dimension 108 has a length greater than or equal to greater than or equal to 10 micrometers, greater than or equal to 50 micrometers, greater than or equal to 100 micrometers, greater than or equal to 500 micrometers, greater than or equal to 0.1 centimeters, greater than or equal to 0.5 centimeters, greater than or equal to 1 centimeter, greater than or equal to 5 centimeters, or greater than or equal to 10 centimeters. Combinations of the above recited ranges are possible (e.g., third dimension 108 has a length of less than or equal to 50 centimeters and greater than or equal to 10 micrometers). Other ranges are also possible.

[0250] In some embodiments, a fiber-reinforced composite comprises a plurality of fibers. FIG. 2B shows, according to certain embodiments, a cross-sectional schematic diagram of the fiber- reinforced composite shown in FIG. 2A, wherein the cross-section is taken along lines 2B shown in FIG. 2A. Referring to FIG. 2B, fiber-reinforced composite 102a comprises plurality of fibers 110.

[0251] In some embodiments, a fiber-reinforced composite comprises a polymer impregnated within the plurality of fibers. In certain embodiments, a fiber-reinforced composite comprises poly(meth)acrylimide impregnated within the plurality of fibers. For example, referring to FIG. 2B, fiber-reinforced composite 102a comprises polymer 112 (e.g., poly(meth)acrylimide) impregnated within the plurality of fibers.

[0252] The poly(meth)acrylimide is foamed, in accordance with certain embodiments. In other embodiments, the poly(meth)acrylimide is unfoamed.

[0253] The fiber-reinforced composite may comprise poly(meth)acrylimide and one or more additional components. In some embodiments, for example, the fiber-reinforced composite

[0254] #14695765vl further comprises one or more of an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, a bismaleimide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylenesulfide, a polyether ketone, a polyether imide, a polyacrylate, a polymethacrylate, a polystyrene, a vinyl ether, a lactone, a blend of two or more of the foregoing, and / or a copolymer of two or more of the foregoing.

[0255] In certain embodiments, the fiber-reinforced composite comprises a plurality of layers (e.g., plies). FIG. 2C shows, according to certain embodiments, a cross-sectional schematic diagram of fiber-reinforced composite 102b comprising a plurality of layers 114 (e.g., layers 114a-114c).

[0256] In some embodiments, each layer (e.g., ply) comprises a polymer (e.g., a poly(meth)acrylimide) impregnated within a plurality of fibers. For example, referring to FIG. 2C, each layer 114 (e.g., layers 114a-114c) comprises polymer 112 (e.g., poly(meth)acrylimide) impregnated within plurality of fibers 110. In some embodiments, each layer is in the form of a sheet, mat, or cloth comprising a plurality of fibers impregnated with a polymer (e.g., a poly(meth)acrylimide).

[0257] In some embodiments, the polymer (e.g., the poly(meth)acrylimide) forms a continuous phase across a boundary of the layers. Referring, for example, to FIG. 2C, polymer 112 (e.g., poly(meth)acrylimide) forms a continuous phase across boundary 116’ (of layers 114a and 114b) and boundary 116” (of layers 114b and 114c). It is also possible for a fiber-reinforced composite to comprise two or more layers that are each impregnated with a polymer, but for which the polymer does not form a continuous phase across the boundary therebetween.

[0258] The plurality of layers may include any of a variety of suitable number of layers. In some embodiments, for example, the fiber-reinforced composite comprises at least 2 layers, at least 3 layers, at least 4 layers, at least 5 layers, at least 10 layers, at least 20 layers, at least 50 layers, at least 100 layers, or more. In some embodiments, the fiber-reinforced composite comprises less than or equal to 500 layers, less than or equal to 100 layers, less than or equal to 50 layers, less than or equal to 20 layers, less than or equal to 10 layers, less than or equal to 5 layers, less than or equal to 4 layers, or less than or equal to 3 layers. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite comprises at least 2 layers and less than or equal to 500 layers). Other ranges are also possible.

[0259] The fiber-reinforced composite may have an advantageously high Tg. The Tgof the fiber-reinforced composite refers to the temperature or temperature range over which the

[0260] #14695765vl polymer of the composite transitions from a glassy, relatively rigid state to a rubby, viscoelastic state.

[0261] The fiber-reinforced composite may have any of a variety of suitable Tgvalues. In some embodiments, for example, the fiber-reinforced composite has a Tggreater than or equal to greater than or equal to 100 °C, greater than or equal to 125 °C, greater than or equal to 150 °C, greater than or equal to 180 °C, greater than or equal to 200 °C, greater than or equal to 225 °C, greater than or equal to 250 °C, greater than or equal to 275 °C, greater than or equal to 300 °C, greater than or equal to 325 °C, greater than or equal to 350 °C, or greater than or equal to 375 °C. In certain embodiments, the fiber-reinforced composite has a Tgless than or equal to 400 °C, less than or equal to 375 °C, less than or equal to 350 °C, less than or equal to 325 °C, less than or equal to 300 °C, less than or equal to 275 °C, less than or equal to 250 °C, less than or equal to 225 °C, less than or equal to 200 °C, less than or equal to 180 °C, less than or equal to 150 °C, or less than or equal to 125 °C. Combinations of the above-recited ranges are possible (e.g., the fiber-reinforced composite has a Tggreater than or equal to 100 °C and less than or equal to 400 °C). Other ranges are also possible. In some non-limiting embodiments, the fiber-reinforced composite has a Tggreater than or equal to 180 °C and less than or equal to 300 °C.

[0262] In certain embodiments, the Tgof the fiber-reinforced composite is determined by ASTM D7028-07R24 (2024 revision).

[0263] In certain embodiments, fiber-reinforced composites comprising a blend of polymers may have an increased Tgvalue as compared to a fiber-reinforced composite that does not include a blend of polymers but is otherwise equivalent. In some non-limiting embodiments, for example, a fiber-reinforced composite comprising a blend of polymers has a Tggreater than or equal to 300 °C and less than or equal to 400 °C.

[0264] The fiber-reinforced composite may have an advantageously high compressive strength (e.g., axial compressive strength and / or transverse compressive strength). The compressive strength of the fiber-reinforced composite refers to the maximum compressive stress that the composite can withstand before failure or permanent deformation. Compressive stress refers to stress applied in a direction substantially parallel to a surface of the composite (e.g., stress applied in a direction parallel, within + / - 1° of parallel, within + / - 5 ° of parallel, within + / - 10 ° of parallel, or within + / - 20 ° of parallel to a surface of the composite). In some embodiments, the compressive strength of the fiber-reinforced composite depends on the orientation of the plurality of fibers.

[0265] #14695765vl The fiber-reinforced composite may have any of a variety of axial compressive strength values. Axial compressive strength refers to the maximum compressive stress the composite can withstand before failure or permanent deformation when compressive stress is applied along an axis that is aligned with a length of the reinforcing fibers. In some embodiments, the fiber- reinforced composite has an axial compressive strength of at least 500 MPa, at least 600 MPa, at least 800 MPa, at least 1000 MPa, or at least 1200 MPa. In certain embodiments, the fiber- reinforced composite has an axial compressive strength less than or equal to 1400 MPa, less than or equal to 1200 MPa, less than or equal to 1000 MPa, less than or equal to 800 MPa, or less than or equal to 600 MPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has an axial compressive strength of at least 500 MPa and less than or equal to 1400 MPa). Other ranges are also possible.

[0266] In certain embodiments, the axial compressive strength of the fiber-reinforced composite is determined by ASTM D6641 / D6641M (2023).

[0267] The fiber-reinforced composite may have any of a variety of transverse compressive strength values. Transverse compressive strength refers to the maximum compressive stress the composite can withstand before failure or permanent deformation when compressive stress is applied along an axis that is perpendicular to the length of the reinforcing fibers. In some embodiments, the fiber-reinforced composite has a transverse compressive strength of at least 50 MPa, at least 75 MPa, at least 100 MPa, at least 125 MPa, at least 150 MPa, or at least 175 MPa. In certain embodiments, the fiber-reinforced composite has a transverse compressive strength less than or equal to 200 MPa, less than or equal to 175 MPa, less than or equal to 150 MPa, less than or equal to 125 MPa, less than or equal to 100 MPa, or less than or equal to 75 MPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a transverse compressive strength of at least 60 MPa and less than or equal to 200 MPa). Other ranges are also possible.

[0268] In certain embodiments, the transverse compressive strength of the fiber-reinforced composite is determined by ASTM D6641 / D6641M (2023).

[0269] The fiber-reinforced composite may have an advantageously high interlaminar shortbeam shear strength. The interlaminar short-beam shear strength of the fiber-reinforced composite refers to the apparent through-thickness shear strength of the composite as determined by a short-beam bending method, and corresponds to the maximum interlaminar shear stress at failure under a short-span three-point bending method. Shear stress refers to stress applied in a direction substantially parallel to a surface of the composite and across the surface of the

[0270] #14695765vl composite (e.g., stress applied in a direction parallel, within + / - 1° of parallel, within + / - 5 ° of parallel, within + / - 10 ° of parallel, or within + / - 20 ° of parallel to a surface of the composite and across the surface of the composite). In some embodiments, the interlaminar short-beam shear strength of the fiber-reinforced composite depends on the orientation of the plurality of fibers.

[0271] The fiber-reinforced composite may have any of a variety of interlaminar short-beam shear strength values. In some embodiments, for example, the fiber-reinforced composite has an interlaminar short-beam shear strength of at least 10 MPa, at least 20 MPa, at least 50 MPa, at least 100 MPa, or at least 150 MPa. In certain embodiments, the fiber-reinforced composite has an interlaminar short-beam shear strength less than or equal to 200 MPa, less than or equal to 150 MPa, less than or equal to 100 MPa, less than or equal to 50 MPa, or less than or equal to 20 MPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has an interlaminar short-beam shear strength of at least lOMPa and less than or equal to 200 MPa). Other ranges are also possible.

[0272] In certain embodiments, the interlaminar short-beam shear strength of the fiber- reinforced composite is determined by ASTM D2344 (2022).

[0273] The fiber-reinforced composite may have an advantageously high tensile strength. The tensile strength of the fiber-reinforced composite refers to the maximum tensile stress that the composite can withstand before fracture or irreversible elongation. Tensile stress refers to stress applied in a direction substantially parallel to a surface of the composite and along a length of the composite (e.g., stress applied in a direction parallel, within + / - 1° of parallel, within + / - 5 ° of parallel, within + / - 10 ° of parallel, or within + / - 20 ° of parallel to a surface of the composite and along a length of the composite). In some embodiments, the tensile strength of the fiber- reinforced composite depends on the orientation of the plurality of fibers.

[0274] The fiber-reinforced composite may have any of a variety of tensile strength values. In some embodiments, for example, the fiber-reinforced composite has a tensile strength of at least 50 MPa, at least 100 MPa, at least 500 MPa, at least 1000 MPa, at least 2000 MPa, or at least 3000 MPa. In certain embodiments, the fiber-reinforced composite has a tensile strength less than or equal to 4000 MPa, less than or equal to 3000 MPa, less than or equal to 2000 MPa, less than or equal to 1000 MPa, less than or equal to 500 MPa or less than or equal to 100 MPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a tensile strength of at least 50 MPa and less than or equal to 4000 MPa). Other ranges are also possible.

[0275] #14695765vl In certain embodiments, the tensile strength of the fiber-reinforced composite is determined by ASTM D3039 / D3039M-23 (2023).

[0276] The fiber-reinforced composite may have an advantageously high tensile modulus. The tensile modulus of the fiber-reinforced composite refers to the ratio of tensile stress to tensile strain within an elastic region of the composite under tensile stress. In some embodiments, the tensile modulus of the fiber-reinforced composite depends on the orientation of the plurality of fibers.

[0277] The fiber-reinforced composite may have any of a variety of tensile modulus values. In some embodiments, for example, the fiber-reinforced composite has a tensile modulus of at least 5 GPa, at least 10 GPa, at least 50 GPa, at least 100 GPa, or at least 200 GPa. In certain embodiments, the fiber-reinforced composite has a tensile modulus of less than or equal to 300 GPa, less than or equal to 200 GPa, less than or equal to 100 GPa, less than or equal to 50 GPa, or less than or equal to 10 GPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a tensile modulus of at least 5 GPa and less than or equal to 300 GPa). Other ranges are also possible.

[0278] In certain embodiments, the tensile modulus of the fiber-reinforced composite is determined by ASTM D3039 / D3039M-23 (2023).

[0279] The fiber-reinforced composite may have an advantageously high elongation at break. The elongation at break of the fiber-reinforced composite refers to the percent extension the composite exhibits at the point of fracture under tensile stress. In some embodiments, the elongation at break of the fiber-reinforced composite depends on the orientation of the plurality of fibers.

[0280] The fiber-reinforced composite may have any of a variety of elongation at break values. In some embodiments, for example, the fiber-reinforced composite has an elongation at break of at least 0.5%, at least 1%, at least 2%, at least 3%, or at least 4%. In certain embodiments, the fiber-reinforced composite has an elongation at break less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, or less than or equal to 1%. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has an elongation at break of at least 0.5% and less than or equal to 5%). Other ranges are also possible.

[0281] In certain embodiments, the elongation at break of the fiber-reinforced composite is determined by ASTM D3039 / D3039M-23 (2023).

[0282] #14695765vl The fiber-reinforced composite may have an advantageously high toughness. The toughness of the fiber-reinforced composite refers to the amount of energy the composite can absorb before fracture.

[0283] The fiber-reinforced composite may have any of a variety of Mode I toughness values. In some embodiments, for example, the fiber-reinforced composite has a Mode I toughness of at least 150 J / m2, at least 500 J / m2, at least 1000 J / m2, at least 1500 J / m2, or at least 2000 J / m2. In certain embodiments, the fiber-reinforced composite has a Mode I toughness less than or equal to 3000 J / m2, less than or equal to 2000 J / m2, less than or equal to 1500 J / m2, less than or equal to 1000 J / m2, or less than or equal to 500 J / m2. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a Mode I toughness of at least 150 J / m2and less than or equal to 3000 J / m2). Other ranges are also possible.

[0284] In certain embodiments, the Mode I toughness of the fiber-reinforced composite is determined by ASTM D5528-23 (2023).

[0285] The fiber-reinforced composite may have any of a variety of Mode II toughness values. In some embodiments, for example, the fiber-reinforced composite has a Mode II toughness of at least 600 J / m2, at least 1000 J / m2, at least 2000 J / m2, at least 3000 J / m2, at least 4000 J / m2, or at least 5000 J / m2. In certain embodiments, the fiber-reinforced composite has a Mode II toughness less than or equal to 6000 J / m2, less than or equal to 5000 J / m2, less than or equal to 4000 J / m2, less than or equal to 3000 J / m2, less than or equal to 2000 J / m2, or less than or equal to 1000 J / m2. Combinations of the above recited ranges are also possible (e.g., the fiber- reinforced composite has a Mode II toughness of at least 600 J / m2and less than or equal to 6000 J / m2). Other ranges are also possible.

[0286] In certain embodiments, the Mode II toughness of the fiber-reinforced composite is determined by ASTM D7905-19 (2019).

[0287] The fiber-reinforced composite may have any of a variety of Mode III toughness values. In some embodiments, for example, the fiber-reinforced composite has a Mode III toughness of at least 25 MJ / m3, at least 50 MJ / m3, at least 100 MJ / m3, at least 150 MJ / m3, or at least 200 J / m3. In certain embodiments, the fiber-reinforced composite has a Mode III toughness less than or equal to 250 MJ / m3, less than or equal to 200 MJ / m3, less than or equal to 150 MJ / m3, less than or equal to 100 MJ / m3, or less than or equal to 50 MJ / m3. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a Mode III toughness of at least 25 MJ / m3and less than or equal to 250 MJ / m3). Other ranges are also possible.

[0288] #14695765vl In certain embodiments, the Mode III toughness of the fiber-reinforced composite is determined by ASTM D7137-20 (2020).

[0289] The fiber-reinforced composite may have an advantageously high creep resistance. The creep resistance of the fiber-reinforced composite refers to the ability of the composite to resist time-dependent deformation when subjected to a sustained load or stress.

[0290] The fiber-reinforced composite may have any of a variety of creep strain values. In some embodiments, for example, the fiber-reinforced composite has a creep strain of less than or equal to 2%, less than or equal to 1.5%, less than or equal to 1%, less than or equal to 0.5%, less than or equal to 0.5%, or less than or equal to 0.2%, less than or equal to 0.1%, or less, over 1,000 hours. In certain embodiments, the fiber-reinforced composite has a creep strain of at least 0.1%, at least 0.2%, at least 0.5%, at least 1%, or at least 1.5% over 1,000 hours. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a creep strain of less than or equal to 2% and at least 0.1% over 1,000 hours). Other ranges are also possible.

[0291] In certain embodiments, the creep resistance of the fiber-reinforced composite is determined by ASTM D2990-21 (2021).

[0292] The fiber-reinforced composite may have an advantageously high impact strength. The impact strength of the fiber-reinforced composite refers to the capacity of the composite to absorb energy and resist fracture under sudden or dynamic loading.

[0293] The fiber-reinforced composite may have any of a variety of impact strength values. In some embodiments, for example, the fiber-reinforced composite has an impact strength of at least 5 J, at least 10 J, at least 20 J, at least 50 J, or at least 100 J. In certain embodiments, the fiber-reinforced composite has an impact strength less than or equal to 150 J, less than or equal to 100 J, less than or equal to 50 J, less than or equal to 20 J, or less than or equal to 10 J. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has an impact strength of at least 5 J and less than or equal to 100 J). Other ranges are also possible.

[0294] In certain embodiments, the impact strength of the fiber-reinforced composite is determined by ASTM D7136-20 (2020).

[0295] The fiber-reinforced composite may have any of a variety of compression-after-impact strength values. In some embodiments, for example, the fiber-reinforced composite has a compression-after-impact of at least 100 MPa, at least 200 MPa, or at least 300 MPa. In certain embodiments, the fiber-reinforced composite has a compression-after-impact strength of less

[0296] #14695765vl than or equal to 400 MPa, less than or equal to 300 MPa, or less than or equal to 200 MPa. Combinations of the above recited ranges are also possible (e.g., the fiber-reinforced composite has a compression-after-impact strength of at least 100 MPa and less than or equal to 400 MPa). Other ranges are also possible.

[0297] In certain embodiments, the impact strength of the fiber-reinforced composite is determined by ASTM D7137-20 (2020).

[0298] The fiber-reinforced composite may have an advantageously high storage modulus. The storage modulus of the fiber-reinforced composite refers to 6,000 MPa, greater than or equal to 8,000 MPa, greater than or equal to 10,000 MPa, greater than or equal to 12,000 MPa, or greater than or equal to 14,000 MPa. In some embodiments, the storage modulus of the

[0299] The fiber-reinforced composite may have any of a variety of suitable storage modulus values. In some embodiments, for example, the fiber-reinforced composite has a storage modulus of greater than or equal to 6,000 MPa, greater than or equal to 8,000 MPa, greater than or equal to 10,000 MPa, greater than or equal to 12,000 MPa, or greater than or equal to 14,000 MPa. In some embodiments, the fiber-reinforced composite has a storage modulus less than or equal to 16,000 MPa, less than or equal to 14,000 MPa, less than or equal to 12,000 MPa, less than or equal to 10,000 MPa, or less than or equal to 8,000 MPa. Combinations of the above recited ranges are possible (e.g., the fiber-reinforced composite has a storage modulus greater than or equal to 6,000 MPa and less than or equal to 16,000 MPa). Other ranges are also possible.

[0300] In some embodiments, the storage modulus of the fiber-reinforced composite is determined by dynamic mechanical analysis (DMA).

[0301] The fiber-reinforced composited may be used in any of a variety of suitable applications. In some embodiments, the fiber-reinforced composites are used in aerospace, automotive, marine, wind energy, sporting goods, and / or civil infrastructure applications. Other applications are also possible.

[0302] Definitions of specific functional groups and chemical terms are described in more detail below. The chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75thEd., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in Thomas Sorrell, Organic Chemistry, University Science Books, Sausalito, 1999;Michael B. Smith, March’s Advanced Organic Chemistry, 7thEdition, John Wiley & Sons, Inc., New York,

[0303] #14695765vl 2013; Richard C. Larock, Comprehensive Organic Transformations, John Wiley & Sons, Inc., New York, 2018; and Carruthers, Some Modern Methods of Organic Synthesis, 3rdEdition, Cambridge University Press, Cambridge, 1987.

[0304] A group is optionally substituted unless expressly provided otherwise. The term “optionally substituted” refers to being substituted or unsubstituted. In certain embodiments, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl groups are optionally substituted. “Optionally substituted” refers to a group which is substituted or unsubstituted (e.g., “substituted” or “unsubstituted” alkyl, “substituted” or “unsubstituted” alkenyl, “substituted” or “unsubstituted” alkynyl, “substituted” or “unsubstituted” heteroalkyl, “substituted” or “unsubstituted” heteroalkenyl, “substituted” or “unsubstituted” heteroalkynyl, “substituted” or “unsubstituted” carbocyclyl, “substituted” or “unsubstituted” heterocyclyl, “substituted” or “unsubstituted” aryl or “substituted” or “unsubstituted” heteroaryl group). In general, the term “substituted” means that at least one hydrogen present on a group is replaced with a permissible substituent, e.g., a substituent which upon substitution results in a stable compound, e.g., a compound which does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, or other reaction.

[0305] Unless otherwise indicated, a “substituted” group has a substituent at one or more substitutable positions of the group, and when more than one position in any given structure is substituted, the substituent is either the same or different at each position. The term “substituted” is contemplated to include substitution with all permissible substituents of organic compounds, and includes any of the substituents described herein that results in the formation of a stable compound. The present disclosure contemplates any and all such combinations in order to arrive at a stable compound. For purposes of this disclosure, heteroatoms such as nitrogen may have hydrogen substituents and / or any suitable substituent as described herein which satisfy the valencies of the heteroatoms and results in the formation of a stable moiety. The disclosure is not limited in any manner by the exemplary substituents described herein.

[0306] In certain embodiments, each oxygen atom substituent is independently substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, or an oxygen protecting group. In certain embodiments, each oxygen atom substituents is independently substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-6 alkyl, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, or an oxygen protecting group, wherein Raais hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, or an oxygen protecting group when attached to an oxygen atom; and

[0307] #14695765vl each Rbbis independently hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, or a nitrogen protecting group. In certain embodiments, each oxygen atom substituent is independently substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-6 alkyl or an oxygen protecting group.

[0308] In certain embodiments, the substituent present on an oxygen atom is an oxygen protecting group (also referred to herein as an “hydroxyl protecting group”). Oxygen protecting groups include -Raa, -N(Rbb)2, -C(=O)SRaa, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, -C(=NRbb)Raa, -C(=NRbb)ORaa, -C(=NRbb)N(Rbb)2, -S(=O)Raa, -SO2Raa, -Si(Raa)3, -P(RCC)2, -P(RCC)3+X“, -P(ORCC)2, -P(ORCC)3+X“, -P(=O)(Raa)2, -P(=O)(ORCC)2, and -P(=O)(N(Rbb)2)2, wherein X“, Raa, Rbb, and Rccare as defined herein. Oxygen protecting groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rdedition, John Wiley & Sons, 1999, incorporated herein by reference.

[0309] Nitrogen atoms can be substituted or unsubstituted as valency permits, and include primary, secondary, tertiary, and quaternary nitrogen atoms. Exemplary nitrogen atom substituents include hydrogen, -OH, -ORaa, -N(RCC)2, -CN, -C(=O)Raa, -C(=O)N(RCC)2, -CO2Raa, -SO2Raa, -C(=NRbb)Raa, -C(=NRcc)ORaa, -C(=NRCC)N(RCC)2, -SO2N(RCC)2, -SO2RCC, -SO2ORCC, -SORaa, -C(=S)N(RCC)2, -C(=O)SRCC, -C(=S)SRCC, -P(=O)(ORCC)2, -P(=O)(Raa)2, -P(=O)(N(RCC)2)2, CI-2O alkyl, Ci-20 perhaloalkyl, Ci-20 alkenyl, Ci-20 alkynyl, hetero Ci-20 alkyl, hetero Ci-20 alkenyl, hetero Ci-20 alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl, or two Rccgroups attached to an N atom are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups, and wherein Raa, Rbb, Rccand Rddare as defined above.

[0310] In certain embodiments, each nitrogen atom substituent is independently substituted (e.g., substituted with one or more halogen) or unsubstituted C1-6 alkyl, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, or a nitrogen protecting group. In certain embodiments, each nitrogen atom substituent is independently substituted (e.g., substituted with one or more halogen) or unsubstituted C1-10 alkyl, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, or a nitrogen protecting group, wherein Raais hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted C1-10 alkyl, or an oxygen protecting group when attached to an oxygen atom; and each Rbbis independently hydrogen, substituted (e.g., substituted with one or more halogen) or

[0311] #14695765vl unsubstituted Ci-io alkyl, or a nitrogen protecting group. In certain embodiments, each nitrogen atom substituent is independently substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-6 alkyl or a nitrogen protecting group.

[0312] In certain embodiments, the substituent present on the nitrogen atom is a nitrogen protecting group (also referred to herein as an “amino protecting group”). Nitrogen protecting groups include -OH, -ORaa, -N(RCC)2, -C(=O)Raa, -C(=O)N(RCC)2, -CO2Raa, -SO2Raa, -C(=NRcc)Raa, -C(=NRcc)ORaa, -C(=NRCC)N(RCC)2, -SO2N(RCC)2, -SO2RCC, -SO2ORCC, -SORaa, -C(=S)N(RCC)2, -C(=O)SRCC, -C(=S)SRCC, CI-IO alkyl (e.g., aralkyl, heteroaralkyl), Ci-20alkenyl, Ci-2o alkynyl, hetero Ci-20 alkyl, hetero Ci-20 alkenyl, hetero Ci-20 alkynyl, C3-10 carbocyclyl, 3- 14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl groups, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aralkyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups, and wherein Raa, Rbb, Rccand Rddare as defined herein. Nitrogen protecting groups are well known in the art and include those described in detail in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3rdedition, John Wiley & Sons, 1999, incorporated herein by reference.

[0313] Exemplary carbon atom substituents include halogen, -CN, -NO2, -N3, -SO2H, -SO3H, -OH, -ORaa, -ON(Rbb)2, -N(Rbb)2, -N(Rbb)3+X“, -N(ORcc)Rbb, -SH, -SRaa, -SSRCC, -C(=O)Raa, -CO2H, -CHO, -C(ORCC)2, -CO2Raa, -OC(=O)Raa, -OCO2Raa, -C(=O)N(Rbb)2, -OC(=O)N(Rbb)2, -NRbbC(=O)Raa, -NRbbCO2Raa, -NRbbC(=O)N(Rbb)2, -C(=NRbb)Raa, -C(=NRbb)ORaa, -OC(=NRbb)Raa, -OC(=NRbb)ORaa, -C(=NRbb)N(Rbb)2, -OC(=NRbb)N(Rbb)2, -NRbbC(=NRbb)N(Rbb)2, -C(=O)NRbbSO2Raa, -NRbbSO2Raa, -SO2N(Rbb)2, -SO2Raa, -SO2ORaa, -OSO2Raa, -S(=O)Raa, -OS(=O)Raa, -Si(Raa)3, -OSi(Raa)3-C(=S)N(Rbb)2, -C(=O)SRaa, -C(=S)SRaa, -SC(=S)SRaa, -SC(=O)SRaa, -OC(=O)SRaa, -SC(=O)ORaa, -SC(=O)Raa, -P(=O)(Raa)2, -P(=O)(ORcc)2, -OP(=O)(Raa)2, -OP(=O)(ORCC)2, -P(=O)(N(Rbb)2)2, -OP(=O)(N(Rbb)2)2, -NRbbP(=O)(Raa)2, -NRbbP(=O)(ORcc)2, -NRbbP(=O)(N(Rbb)2)2, -P(RCC)2, -P(ORCC)2, -P(RCC)3+X“, -P(ORCC)3+X“, -P(RCC)4, -P(ORCC)4, -OP(RCC)2, -OP(RCC)3+X“, -OP(ORCC)2, -OP(ORCC)3+X-, -OP(RCC)4, -OP(ORcc)4, -B(Raa)2, -B(ORCC)2, -BRaa(ORcc), Ci -20 alkyl, Ci-20 perhaloalkyl, Ci-20 alkenyl, Ci-20 alkynyl, heteroCi-2o alkyl, heteroCi-2o alkenyl, heteroCi-2o alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; wherein X“ is a counterion;

[0314] #14695765vl or two geminal hydrogens on a carbon atom are replaced with the group =0, =S, =NN(Rbb)2, =NNRbbC(=O)Raa, =NNRbbC(=O)ORaa, =NNRbbS(=O)2Raa, =NRbb, or =NORCC; wherein: each instance of Raais, independently, selected from Ci-20 alkyl, Ci-20 perhaloalkyl, Ci-20 alkenyl, Ci-20 alkynyl, heteroCi-20 alkyl, heteroCi-2oalkenyl, heteroCi-2oalkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl, or two Raagroups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each of the alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; each instance of Rbbis, independently, selected from hydrogen, -OH, -ORaa, -N(RCC)2, -CN, -C(=O)Raa, -C(=O)N(RCC)2, -CO2Raa, -SO2Raa, -C(=NRcc)ORaa, -C(=NRCC)N(RCC)2, -SO2N(RCC)2, -SO2RCC, -SO2ORCC, -SORaa, -C(=S)N(RCC)2, -C(=O)SRCC, -C(=S)SRCC, -P(=O)(Raa)2, -P(=O)(ORCC)2, -P(=O)(N(RCC)2)2, Ci-2o alkyl, C1-20 perhaloalkyl, Ci-20 alkenyl, Ci-20 alkynyl, heteroCi-2oalkyl, heteroCi-2oalkenyl, heteroCi-2oalkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl, or two Rbbgroups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; each instance of Rccis, independently, selected from hydrogen, Ci-20 alkyl, Ci-20 perhaloalkyl, Ci-20 alkenyl, Ci-20 alkynyl, heteroCi-20 alkyl, heteroCi-20 alkenyl, heteroCi-20 alkynyl, C3-10 carbocyclyl, 3-14 membered heterocyclyl, Ce-14 aryl, and 5-14 membered heteroaryl, or two Rccgroups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rddgroups; each instance of Rddis, independently, selected from halogen, -CN, -NO2, -N3, -SO2H, -SO3H, -OH, -ORee, -ON(Rff)2, -N(Rff)2, -N(Rff)3+X’, -N(ORee)Rff, -SH, -SRee, -SSRee, -C(=O)Ree, -CO2H, -CO2Ree, -OC(=O)Ree, -OCO2Ree, -C(=O)N(Rff)2, -OC(=O)N(Rff)2, -NRffC(=O)Ree, -NRffCO2Ree, -NRffC(=O)N(Rff)2, -C(=NRff)ORee, -OC(=NRff)Ree, -OC(=NRff)ORee, -C(=NRff)N(Rff)2, -OC(=NRff)N(Rff)2, -NRffC(=NRff)N(Rff)2, -NRffSO2Ree, -SO2N(Rff)2, -SO2Ree, -SO2ORee, -OSO2Ree,

[0315] #14695765vl -S(=O)Ree, — Si(Ree)3, -OSi(Ree)3, -C(=S)N(Rff)2, -C(=O)SRee, -C(=S)SRee, -SC(=S)SRee, -P(=O)(ORee)2, -P(=O)(Ree)2, -OP(=O)(Ree)2, -OP(=O)(ORee)2, Ci-io alkyl, Ci-io perhaloalkyl, Ci-io alkenyl, Ci-io alkynyl, heteroCi-ioalkyl, heteroCi- walkenyl, heteroCi-ioalkynyl, C3-10 carbocyclyl, 3-10 membered heterocyclyl, Ce-io aryl, and 5-10 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups, or two geminal Rddsubstituents are joined to form =0 or =S; wherein X“ is a counterion; each instance of Reeis, independently, selected from Ci-10 alkyl, Ci-10 perhaloalkyl, Ci-10 alkenyl, Ci-10 alkynyl, heteroCi-10 alkyl, heteroCi-10 alkenyl, heteroCi-10 alkynyl, C3-10 carbocyclyl, Ce-io aryl, 3-10 membered heterocyclyl, and 3-10 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups; each instance of Rffis, independently, selected from hydrogen, Ci-10 alkyl, Ci-10 perhaloalkyl, Ci-10 alkenyl, Ci-10 alkynyl, heteroCi-10 alkyl, heteroCi-10 alkenyl, heteroCi-10 alkynyl, C3-10 carbocyclyl, 3-10 membered heterocyclyl, Ce-io aryl, and 5-10 membered heteroaryl, or two Rffgroups are joined to form a 3-10 membered heterocyclyl or 5-10 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 Rgggroups; each instance of Rggis, independently, halogen, -CN, -NO2, -N3, -SO2H, -SO3H, -OH, -OCi-6 alkyl, -ON(Ci-6alkyl)2, -N(Ci^ alkyl)2, -N(Ci^ alkyl^X’, -NH(CI-6 alkyl)2+X“, -NH2(CI6alkyl)+X“, -NH3+X“, -NfOCi alkyl)(Ci-6 alkyl), -N(OH)(CI-6 alkyl), -NH(OH), -SH, -SCi-6alkyl, -SS(Ci-6alkyl), -C(=O)(Ci-6 alkyl), -CO2H, -CO2(Ci 6 alkyl), -OC(=O)(Ci-6 alkyl), -OCO2(Ci alkyl), -C(=O)NH2, -C(=O)N(CI-6 alkyl)2, -OC(=O)NH(Ci6alkyl), -NHC(=O)( Ci-6alkyl), -N(Ci-6 alkyl)C(=O)( Ci alkyl), -NHCO2(CI 6 alkyl), -NHC(=O)N(Ci-6alkyl)2, -NHC(=O)NH(CI-6alkyl), -NHC(=O)NH2, -C(=NH)O(Ci6alkyl), -OC(=NH)(Ci6alkyl), -OC(=NH)OCI-6alkyl, -C(=NH)N(Ci6alkyl)2, -C(=NH)NH(Ci6alkyl), -C(=NH)NH2, -OC(=NH)N(CI-6alkyl)2, -OC(NH)NH(Ci6alkyl), -OC(NH)NH2, -NHC(NH)N(CI-6alkyl)2, -NHC(=NH)NH2, -NHSO2(C I6alkyl), -SO2N(CI6alkyl)2, -SO2NH(C I 6 alkyl), -SO2NH2, -SO2C16alkyl, -SO2OC16alkyl, -OSO2C16alkyl,

[0316] #14695765vl -SOCi-6 alkyl, -Si(Ci-6alkyl)3, -OSi(Ci-6alkyl)3-C(=S)N(Ci-6 alkyl)2, C(=S)NH(Ci-6alkyl), C(=S)NH2, -C(=O)S(CI^ alkyl), -C(=S)SCi^ alkyl, -SC(=S)SCi-6alkyl, -P(=O)(OCi-6 alkyl)2, -P(=O)(Ci-6 alkyl)2, -OP(=O)(Ci-6 alkyl)2, -OP(=O)(OCi6alkyl)2, Ci-io alkyl, Ci-io perhaloalkyl, Ci-io alkenyl, Ci-io alkynyl, heteroCi-io alkyl, heteroCi-io alkenyl, heteroCi-io alkynyl, C3-io carbocyclyl, Ce-io aryl, 3-10 membered heterocyclyl, or 5-10 membered heteroaryl; or two geminal Rggsubstituents can be joined to form =0 or =S: and each X“ is a counterion.

[0317] In certain embodiments, each carbon atom substituent is independently halogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-6 alkyl, -ORaa, -SR33, -N(Rbb)2, -CN, -SCN, -NO2, -C(=O)Raa, -CO2Raa, -C(=O)N(Rbb)2, -OC(=O)Raa, -OCO2R33, -OC(=O)N(Rbb)2, -NRbbC(=0)R33, -NRbbCO2Raa, or -NRbbC(=O)N(Rbb)2. In certain embodiments, each carbon atom substituent is independently halogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci- io alkyl, -OR33, -SRaa, -N(Rbb)2, - -OC(=O)N(Rbb)2, -NRbbC(=0)R33, -NRbbCO2Raa, or -NRbbC(=O)N(Rbb)2, wherein Raais hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, an oxygen protecting group (e.g., silyl, TBDPS, TBDMS, TIPS, TES, TMS, MOM, THP, t-Bu, Bn, allyl, acetyl, pivaloyl, or benzoyl) when attached to an oxygen atom, or a sulfur protecting group (e.g., acetamidomethyl, t-Bu, 3-nitro-2-pyridine sulfenyl, 2-pyridine- sulfenyl, or triphenylmethyl) when attached to a sulfur atom; and each Rbbis independently hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, or a nitrogen protecting group (e.g., Bn, Boc, Cbz, Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts). In certain embodiments, each carbon atom substituent is independently halogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-6 alkyl, -OR351, -SRaa, -N(Rbb)2, -CN, -SCN, or -NO2. In certain embodiments, each carbon atom substituent is independently halogen, substituted (e.g., substituted with one or more halogen moieties) or unsubstituted Ci-io alkyl, -ORaa, -SR33, -N(Rbb)2, -CN, -SCN, or -NO2, wherein R33is hydrogen, substituted (e.g., substituted with one or more halogen) or unsubstituted Ci-io alkyl, an oxygen protecting group (e.g., silyl, TBDPS, TBDMS, TIPS, TES, TMS, MOM, THP, t-Bu, Bn, allyl, acetyl, pivaloyl, or benzoyl) when attached to an oxygen atom, or a sulfur protecting group (e.g., acetamidomethyl, t-Bu, 3-nitro-2-pyridine sulfenyl, 2-pyridine- sulfenyl, or triphenylmethyl) when attached to a sulfur atom; and each Rbbis independently hydrogen, substituted (e.g., substituted with one or

[0318] #14695765vl more halogen) or unsubstituted Ci-io alkyl, or a nitrogen protecting group (e.g., Bn, Boe, Cbz, Fmoc, trifluoroacetyl, triphenylmethyl, acetyl, or Ts).

[0319] In certain embodiments, the molecular weight of an optional substituent is lower than 250, lower than 200, lower than 150, lower than 100, or lower than 50 g / mol.

[0320] Compounds described herein can comprise one or more asymmetric centers, and thus can exist in various stereoisomeric forms, e.g., enantiomers and / or diastereomers. For example, the compounds described herein can be in the form of an individual enantiomer, diastereomer or geometric isomer, or can be in the form of a mixture of stereoisomers, including racemic mixtures and mixtures enriched in one or more stereoisomer. Isomers can be isolated from mixtures by methods known to those skilled in the art, including chiral high pressure liquid chromatography (HPLC) and the formation and crystallization of chiral salts; or preferred isomers can be prepared by asymmetric syntheses. See, for example, Jacques et al., Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen et al., Tetrahedron 33:2725 (1977); Eliel, E.L. Stereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); and Wilen, S.H., Tables of Resolving Agents and Optical Resolutions p. 268 (E.L. Eliel, Ed., Univ, of Notre Dame Press, Notre Dame, IN 1972). The invention additionally encompasses compounds as individual isomers substantially free of other isomers, and alternatively, as mixtures of various isomers.

[0321] When a range of values is listed, it is intended to encompass each value and sub-range within the range. A range is inclusive of the values at the two ends of the range unless otherwise provided. For example, “Ci-6 alkyl” encompasses, Ci, C2, C3, C4, C5, Cs, Cis, Cis, Cis, Cis, C1-2, C2-6, C2-5, C2-4, C2-3, C3-6, C3-5, C3-4, C4-6, C4-5, and C5-6 alkyl.

[0322] The term “aliphatic” refers to alkyl, alkenyl, alkynyl, and carbocyclic groups. Likewise, the term “heteroaliphatic” refers to heteroalkyl, heteroalkenyl, heteroalkynyl, and heterocyclic groups.

[0323] The term “alkyl” refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 20 carbon atoms (“Ci-20 alkyl”). In some embodiments, an alkyl group has 1 to 12 carbon atoms (“Ci-12 alkyl”). In some embodiments, an alkyl group has 1 to 10 carbon atoms (“Ci-10 alkyl”). In some embodiments, an alkyl group has 1 to 9 carbon atoms (“C1-9 alkyl”). In some embodiments, an alkyl group has 1 to 8 carbon atoms (“Ci-8 alkyl”). In some embodiments, an alkyl group has 1 to 7 carbon atoms (“C1-7 alkyl”). In some embodiments, an alkyl group has 1 to 6 carbon atoms (“Ci-6 alkyl”). In some embodiments, an alkyl group has 1 to 5 carbon atoms (“C1-5 alkyl”). In some embodiments, an alkyl group has 1

[0324] #14695765vl to 4 carbon atoms (“Ci-4 alkyl”). In some embodiments, an alkyl group has 1 to 3 carbon atoms (“Ci-3 alkyl”). In some embodiments, an alkyl group has 1 to 2 carbon atoms (“C1-2 alkyl”). In some embodiments, an alkyl group has 1 carbon atom (“Ci alkyl”). In some embodiments, an alkyl group has 2 to 6 carbon atoms (“C2-6 alkyl”). Examples of Ci-6 alkyl groups include methyl (Ci), ethyl (C2), propyl (C3) (e.g., n-propyl, isopropyl), butyl (C4) (e.g., n-butyl, tert-butyl, secbutyl, isobutyl), pentyl (C5) (e.g., n-pentyl, 3-pentanyl, amyl, neopentyl, 3-methyl-2-butanyl, tert-amyl), and hexyl (Ce) (e.g., n-hexyl). Additional examples of alkyl groups include n-heptyl (C7), n-octyl (Cs), n-dodecyl (C12), and the like. Unless otherwise specified, each instance of an alkyl group is independently unsubstituted (an “unsubstituted alkyl”) or substituted (a “substituted alkyl”) with one or more substituents (e.g., halogen, such as F). In certain embodiments, the alkyl group is an unsubstituted Ci-12 alkyl (such as unsubstituted Ci-6 alkyl, e.g., -CH3 (Me), unsubstituted ethyl (Et), unsubstituted propyl (Pr, e.g., unsubstituted n-propyl (n-Pr), unsubstituted isopropyl (z-Pr)), unsubstituted butyl (Bu, e.g., unsubstituted n-butyl (n- Bu), unsubstituted tert-butyl (tert-Bu or t-Bu), unsubstituted sec-butyl (sec-Bu or s-Bu), unsubstituted isobutyl (z-Bu)). In certain embodiments, the alkyl group is a substituted Ci-12 alkyl (such as substituted Ci-6 alkyl, e.g., -CH2F, -CHF2, -CF3, -CH2CH2F, -CH2CHF2, - CH2CF3, or benzyl (Bn)).

[0325] The term “heteroalkyl” refers to an alkyl group, which further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur within (e.g., inserted between adjacent carbon atoms of) and / or placed at one or more terminal position(s) of the parent chain. In certain embodiments, a heteroalkyl group refers to a saturated group having from 1 to 20 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-20 alkyl”). In certain embodiments, a heteroalkyl group refers to a saturated group having from 1 to 12 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-12 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 11 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-n alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 10 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-10 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 9 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-9 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 8 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-s alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 7 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-7 alkyl”). In some embodiments, a heteroalkyl

[0326] #14695765vl group is a saturated group having 1 to 6 carbon atoms and 1 or more heteroatoms within the parent chain (“heteroCi-6 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 5 carbon atoms and 1 or 2 heteroatoms within the parent chain (“heteroCi-5 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 4 carbon atoms and lor 2 heteroatoms within the parent chain (“heteroCi-4 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 3 carbon atoms and 1 heteroatom within the parent chain (“heteroCi-3 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 to 2 carbon atoms and 1 heteroatom within the parent chain (“heteroCi-2 alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 1 carbon atom and 1 heteroatom (“heteroCi alkyl”). In some embodiments, a heteroalkyl group is a saturated group having 2 to 6 carbon atoms and 1 or 2 heteroatoms within the parent chain (“heteroC2-6 alkyl”). Unless otherwise specified, each instance of a heteroalkyl group is independently unsubstituted (an “unsubstituted heteroalkyl”) or substituted (a “substituted heteroalkyl”) with one or more substituents. In certain embodiments, the heteroalkyl group is an unsubstituted heteroCi-12 alkyl. In certain embodiments, the heteroalkyl group is a substituted heteroCi-12 alkyl.

[0327] The term “alkenyl” refers to a radical of a straight-chain or branched hydrocarbon group having from 1 to 20 carbon atoms and one or more carbon-carbon double bonds (e.g., 1, 2, 3, or 4 double bonds). In some embodiments, an alkenyl group has 1 to 20 carbon atoms (“C1-20 alkenyl”). In some embodiments, an alkenyl group has 1 to 12 carbon atoms (“Ci-12 alkenyl”). In some embodiments, an alkenyl group has 1 to 11 carbon atoms (“Ci-11 alkenyl”). In some embodiments, an alkenyl group has 1 to 10 carbon atoms (“Ci-10 alkenyl”). In some embodiments, an alkenyl group has 1 to 9 carbon atoms (“C1-9 alkenyl”). In some embodiments, an alkenyl group has 1 to 8 carbon atoms (“Ci-8 alkenyl”). In some embodiments, an alkenyl group has 1 to 7 carbon atoms (“C1-7 alkenyl”). In some embodiments, an alkenyl group has 1 to 6 carbon atoms (“Ci-6 alkenyl”). In some embodiments, an alkenyl group has 1 to 5 carbon atoms (“C1-5 alkenyl”). In some embodiments, an alkenyl group has 1 to 4 carbon atoms (“Ci^i alkenyl”). In some embodiments, an alkenyl group has 1 to 3 carbon atoms (“C1-3 alkenyl”). In some embodiments, an alkenyl group has 1 to 2 carbon atoms (“C1-2 alkenyl”). In some embodiments, an alkenyl group has 1 carbon atom (“Ci alkenyl”). The one or more carboncarbon double bonds can be internal (such as in 2-butenyl) or terminal (such as in 1-butenyl). Examples of Ci^i alkenyl groups include methylidenyl (Ci), ethenyl (C2), 1-propenyl (C3), 2- propenyl (C3), 1-butenyl (C4), 2-butenyl (C4), butadienyl (C4), and the like. Examples of Ci-6 alkenyl groups include the aforementioned C2-4 alkenyl groups as well as pentenyl (C5),

[0328] #14695765vl pentadienyl (Cs), hexenyl (Ce), and the like. Additional examples of alkenyl include heptenyl (C7), octenyl (Cs), octatrienyl (Cs), and the like. Unless otherwise specified, each instance of an alkenyl group is independently unsubstituted (an “unsubstituted alkenyl”) or substituted (a “substituted alkenyl”) with one or more substituents. In certain embodiments, the alkenyl group is an unsubstituted C1-20 alkenyl. In certain embodiments, the alkenyl group is a substituted C1-20 alkenyl. In an alkenyl group, a C=C double bond for which the stereochemistry is not specified -configuration.

[0329] The term “heteroalkenyl” refers to an alkenyl group, which further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur within (e.g., inserted between adjacent carbon atoms of) and / or placed at one or more terminal position(s) of the parent chain. In certain embodiments, a heteroalkenyl group refers to a group having from 1 to 20 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-20 alkenyl”). In certain embodiments, a heteroalkenyl group refers to a group having from 1 to 12 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-12 alkenyl”). In certain embodiments, a heteroalkenyl group refers to a group having from 1 to 11 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-11 alkenyl”). In certain embodiments, a heteroalkenyl group refers to a group having from 1 to 10 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-10 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 9 carbon atoms at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-9 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 8 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-8 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 7 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-7 alkenyl”). In some embodiments, a heteroalkenyl group has Ito 6 carbon atoms, at least one double bond, and 1 or more heteroatoms within the parent chain (“heteroCi-6 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 5 carbon atoms, at least one double bond, and 1 or 2 heteroatoms within the parent chain (“heteroCi-5 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 4 carbon atoms, at least one double bond, and 1 or 2 heteroatoms within the parent chain (“heteroC 1 4 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 3 carbon atoms, at least one double bond, and 1 heteroatom within the parent chain (“heteroCi-3 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 2 carbon atoms, at least one double bond, and 1

[0330] #14695765vl heteroatom within the parent chain (“heteroCi-2 alkenyl”). In some embodiments, a heteroalkenyl group has 1 to 6 carbon atoms, at least one double bond, and 1 or 2 heteroatoms within the parent chain (“heteroCi-6 alkenyl”). Unless otherwise specified, each instance of a heteroalkenyl group is independently unsubstituted (an “unsubstituted heteroalkenyl”) or substituted (a “substituted heteroalkenyl”) with one or more substituents. In certain embodiments, the heteroalkenyl group is an unsubstituted heteroCi-20 alkenyl. In certain embodiments, the heteroalkenyl group is a substituted heteroCi-20 alkenyl.

[0331] The term “alkynyl” refers to a radical of a straight-chain or branched hydrocarbon group having from 1 to 20 carbon atoms and one or more carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds) (“C1-20 alkynyl”). In some embodiments, an alkynyl group has 1 to 10 carbon atoms (“Ci-10 alkynyl”). In some embodiments, an alkynyl group has 1 to 9 carbon atoms (“C1-9 alkynyl”). In some embodiments, an alkynyl group has 1 to 8 carbon atoms (“C1-8 alkynyl”). In some embodiments, an alkynyl group has 1 to 7 carbon atoms (“C1-7 alkynyl”). In some embodiments, an alkynyl group has 1 to 6 carbon atoms (“C1-6 alkynyl”). In some embodiments, an alkynyl group has 1 to 5 carbon atoms (“C1-5 alkynyl”). In some embodiments, an alkynyl group has 1 to 4 carbon atoms (“C1-4 alkynyl”). In some embodiments, an alkynyl group has 1 to 3 carbon atoms (“C1-3 alkynyl”). In some embodiments, an alkynyl group has 1 to 2 carbon atoms (“C1-2 alkynyl”). In some embodiments, an alkynyl group has 1 carbon atom (“Ci alkynyl”). The one or more carbon-carbon triple bonds can be internal (such as in 2-butynyl) or terminal (such as in 1-butynyl). Examples of C1-4 alkynyl groups include, without limitation, methylidynyl (Ci), ethynyl (C2), 1-propynyl (C3), 2-propynyl (C3), 1-butynyl (C4), 2-butynyl (C4), and the like. Examples of C1-6 alkenyl groups include the aforementioned C2-4 alkynyl groups as well as pentynyl (C5), hexynyl (Ce), and the like. Additional examples of alkynyl include heptynyl (C7), octynyl (Cs), and the like. Unless otherwise specified, each instance of an alkynyl group is independently unsubstituted (an “unsubstituted alkynyl”) or substituted (a “substituted alkynyl”) with one or more substituents. In certain embodiments, the alkynyl group is an unsubstituted C1-20 alkynyl. In certain embodiments, the alkynyl group is a substituted C1-20 alkynyl.

[0332] The term “heteroalkynyl” refers to an alkynyl group, which further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur within (e.g., inserted between adjacent carbon atoms of) and / or placed at one or more terminal position(s) of the parent chain. In certain embodiments, a heteroalkynyl group refers to a group having from 1 to 20 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain

[0333] #14695765vl (“heteroCi-20 alkynyl”). In certain embodiments, a heteroalkynyl group refers to a group having from 1 to 10 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain (“heteroCi-io alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 9 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain (“heteroCi-9 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 8 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain (“heteroCi-8 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 7 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain (“heteroCi-7 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 6 carbon atoms, at least one triple bond, and 1 or more heteroatoms within the parent chain (“heteroCi-6 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 5 carbon atoms, at least one triple bond, and 1 or 2 heteroatoms within the parent chain (“heteroCi-5 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 4 carbon atoms, at least one triple bond, and lor 2 heteroatoms within the parent chain (“heteroCi-4 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 3 carbon atoms, at least one triple bond, and 1 heteroatom within the parent chain (“heteroCi-3 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 2 carbon atoms, at least one triple bond, and 1 heteroatom within the parent chain (“heteroCi-2 alkynyl”). In some embodiments, a heteroalkynyl group has 1 to 6 carbon atoms, at least one triple bond, and 1 or 2 heteroatoms within the parent chain (“heteroCi-6 alkynyl”). Unless otherwise specified, each instance of a heteroalkynyl group is independently unsubstituted (an “unsubstituted heteroalkynyl”) or substituted (a “substituted heteroalkynyl”) with one or more substituents. In certain embodiments, the heteroalkynyl group is an unsubstituted heteroCi-20 alkynyl. In certain embodiments, the heteroalkynyl group is a substituted heteroCi-20 alkynyl.

[0334] The term “carbocyclyl” or “carbocyclic” refers to a radical of a non-aromatic cyclic hydrocarbon group having from 3 to 14 ring carbon atoms (“C3-14 carbocyclyl”) and zero heteroatoms in the non-aromatic ring system. In some embodiments, a carbocyclyl group has 3 to 14 ring carbon atoms (“C3-14 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 13 ring carbon atoms (“C3-13 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 12 ring carbon atoms (“C3-12 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 11 ring carbon atoms (“C3-11 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 10 ring carbon atoms (“C3-10 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 8 ring carbon atoms (“C3-8 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 7 ring carbon atoms (“C3-7 carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 6

[0335] #14695765vl ring carbon atoms (“C3-6 carbocyclyl”). In some embodiments, a carbocyclyl group has 4 to 6 ring carbon atoms (“C4-6 carbocyclyl”). In some embodiments, a carbocyclyl group has 5 to 6 ring carbon atoms (“C5-6 carbocyclyl”). In some embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C5-10 carbocyclyl”). Exemplary C3-6 carbocyclyl groups include cyclopropyl (C3), cyclopropenyl (C3), cyclobutyl (C4), cyclobutenyl (C4), cyclopentyl (C5), cyclopentenyl (C5), cyclohexyl (Ce), cyclohexenyl (Ce), cyclohexadienyl (Ce), and the like. Exemplary C3-8 carbocyclyl groups include the aforementioned C3-6 carbocyclyl groups as well as cycloheptyl (C7), cycloheptenyl (C7), cycloheptadienyl (C7), cycloheptatrienyl (C7), cyclooctyl (Cs), cyclooctenyl (Cs), bicyclo[2.2.1]heptanyl (C7), bicyclo[2.2.2]octanyl (Cs), and the like.

[0336] Exemplary C3-10 carbocyclyl groups include the aforementioned C3-8 carbocyclyl groups as well as cyclononyl (C9), cyclononenyl (C9), cyclodecyl (C10), cyclodecenyl (C10), octahydro- 1H- indenyl (C9), decahydronaphthalenyl (C10), spiro[4.5]decanyl (C10), and the like. Exemplary C3-8 carbocyclyl groups include the aforementioned C3-10 carbocyclyl groups as well as cycloundecyl (Cn), spiro[5.5]undecanyl (C11), cyclododecyl (C12), cyclododecenyl (C12), cyclotridecane (C13), cyclotetradecane (C14), and the like. As the foregoing examples illustrate, in certain embodiments, the carbocyclyl group is either monocyclic (“monocyclic carbocyclyl”) or polycyclic (e.g., containing a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic carbocyclyl”) or tricyclic system (“tricyclic carbocyclyl”)) and can be saturated or can contain one or more carbon-carbon double or triple bonds. “Carbocyclyl” also includes ring systems wherein the carbocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups wherein the point of attachment is on the carbocyclyl ring, and in such instances, the number of carbons continue to designate the number of carbons in the carbocyclic ring system. Unless otherwise specified, each instance of a carbocyclyl group is independently unsubstituted (an “unsubstituted carbocyclyl”) or substituted (a “substituted carbocyclyl”) with one or more substituents. In certain embodiments, the carbocyclyl group is an unsubstituted C3-14 carbocyclyl. In certain embodiments, the carbocyclyl group is a substituted C3-14 carbocyclyl.

[0337] In some embodiments, “carbocyclyl” is a monocyclic, saturated carbocyclyl group having from 3 to 14 ring carbon atoms (“C3-14 cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 10 ring carbon atoms (“C3-10 cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 8 ring carbon atoms (“C3-8 cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 6 ring carbon atoms (“C3-6 cycloalkyl”). In some embodiments, a cycloalkyl group has 4 to 6 ring carbon atoms (“C4-6 cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 6 ring carbon atoms (“C5-6 cycloalkyl”). In some embodiments, a cycloalkyl

[0338] #14695765vl -H- group has 5 to 10 ring carbon atoms (“C5-10 cycloalkyl”). Examples of C5-6 cycloalkyl groups include cyclopentyl (C5) and cyclohexyl (C5). Examples of C3-6 cycloalkyl groups include the aforementioned C5-6 cycloalkyl groups as well as cyclopropyl (C3) and cyclobutyl (C4). Examples of C3-8 cycloalkyl groups include the aforementioned C3-6 cycloalkyl groups as well as cycloheptyl (C7) and cyclooctyl (Cs). Unless otherwise specified, each instance of a cycloalkyl group is independently unsubstituted (an “unsubstituted cycloalkyl”) or substituted (a “substituted cycloalkyl”) with one or more substituents. In certain embodiments, the cycloalkyl group is an unsubstituted C3-14 cycloalkyl. In certain embodiments, the cycloalkyl group is a substituted C3-14 cycloalkyl. In certain embodiments, the carbocyclyl includes 0, 1, or 2 C=C double bonds in the carbocyclic ring system, as valency permits.

[0339] The term “heterocyclyl” or “heterocyclic” refers to a radical of a 3- to 14-membered nonaromatic ring system having ring carbon atoms and 1 to 4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“3-14 membered heterocyclyl”). In heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”) or polycyclic (e.g., a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic heterocyclyl”) or tricyclic system (“tricyclic heterocyclyl”)), and can be saturated or can contain one or more carbon-carbon double or triple bonds. Heterocyclyl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heterocyclyl” also includes ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more carbocyclyl groups wherein the point of attachment is either on the carbocyclyl or heterocyclyl ring, or ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclyl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heterocyclyl ring system. Unless otherwise specified, each instance of heterocyclyl is independently unsubstituted (an “unsubstituted heterocyclyl”) or substituted (a “substituted heterocyclyl”) with one or more substituents. In certain embodiments, the heterocyclyl group is an unsubstituted 3-14 membered heterocyclyl. In certain embodiments, the heterocyclyl group is a substituted 3-14 membered heterocyclyl. In certain embodiments, the heterocyclyl is substituted or unsubstituted, 3- to 7-membered, monocyclic heterocyclyl, wherein 1, 2, or 3 atoms in the heterocyclic ring system are independently oxygen, nitrogen, or sulfur, as valency permits.

[0340] #14695765vl In some embodiments, a heterocyclyl group is a 5-10 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-8 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-6 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur.

[0341] Exemplary 3-membered heterocyclyl groups containing 1 heteroatom include azirdinyl, oxiranyl, and thiiranyl. Exemplary 4-membered heterocyclyl groups containing 1 heteroatom include azetidinyl, oxetanyl, and thietanyl. Exemplary 5-membered heterocyclyl groups containing 1 heteroatom include tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl, and pyrrolyl-2, 5-dione. Exemplary 5- membered heterocyclyl groups containing 2 heteroatoms include dioxolanyl, oxathiolanyl and dithiolanyl. Exemplary 5-membered heterocyclyl groups containing 3 heteroatoms include triazolinyl, oxadiazolinyl, and thiadiazolinyl. Exemplary 6-membered heterocyclyl groups containing 1 heteroatom include piperidinyl, tetrahydropyranyl, dihydropyridinyl, and thianyl. Exemplary 6-membered heterocyclyl groups containing 2 heteroatoms include piperazinyl, morpholinyl, dithianyl, and dioxanyl. Exemplary 6-membered heterocyclyl groups containing 3 heteroatoms include triazinyl. Exemplary 7-membered heterocyclyl groups containing 1 heteroatom include azepanyl, oxepanyl and thiepanyl. Exemplary 8-membered heterocyclyl groups containing 1 heteroatom include azocanyl, oxecanyl and thiocanyl. Exemplary bicyclic heterocyclyl groups include indolinyl, isoindolinyl, dihydrobenzofuranyl, dihydrobenzothienyl, tetrahydrobenzothienyl, tetrahydrobenzofuranyl, tetrahydroindolyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, decahydroisoquinolinyl, octahydrochromenyl, octahydroisochromenyl, decahydronaphthyridinyl, decahydro- 1 ,8-naphthyridinyl, octahydropyrrolo[3,2-b]pyrrole, indolinyl, phthalimidyl, naphthalimidyl, chromanyl, chromenyl, 1 H-benzo [e] [ 1 ,4] diazepinyl, 1 ,4,5 ,7-tetrahydropyrano [3 ,4-b]pyrrolyl, 5 ,6-dihydro-4H-furo [3,2-

[0342] #14695765vl b]pyrrolyl, 6,7-dihydro-5H-furo[3,2-b]pyranyl, 5,7-dihydro-4H-thieno[2,3-c]pyranyl, 2,3- dihydro- lH-pyrrolo[2,3-b]pyridinyl, 2,3-dihydrofuro[2,3-b]pyridinyl, 4,5,6,7-tetrahydro- 1H- pyrrolo[2,3-b]pyridinyl, 4,5,6,7-tetrahydrofuro[3,2-c]pyridinyl, 4,5,6,7-tetrahydrothieno[3,2- b]pyridinyl, l,2,3,4-tetrahydro-l,6-naphthyridinyl, and the like.

[0343] The term “aryl” refers to a radical of a monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 u electrons shared in a cyclic array) having 6-14 ring carbon atoms and zero heteroatoms provided in the aromatic ring system (“Ce-14 aryl”). In some embodiments, an aryl group has 6 ring carbon atoms (“Ce aryl”; e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms (“Cio aryl”; e.g., naphthyl such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms (“Ci4 aryl”; e.g., anthracyl). “Aryl” also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Unless otherwise specified, each instance of an aryl group is independently unsubstituted (an “unsubstituted aryl”) or substituted (a “substituted aryl”) with one or more substituents. In certain embodiments, the aryl group is an unsubstituted Ce-14 aryl. In certain embodiments, the aryl group is a substituted Ce-14 aryl.

[0344] The term “heteroaryl” refers to a radical of a 5-14 membered monocyclic or polycyclic (e.g., bicyclic, tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 n electrons shared in a cyclic array) having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-14 membered heteroaryl”). In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl polycyclic ring systems can include one or more heteroatoms in one or both rings. “Heteroaryl” includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the point of attachment is on the heteroaryl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heteroaryl ring system. “Heteroaryl” also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, and in such instances, the number of ring members designates the number of ring members in the fused polycyclic (aryl / heteroaryl) ring system. Polycyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g.,

[0345] #14695765vl indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, e.g., either the ring bearing a heteroatom e.g., 2-indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl). In certain embodiments, the heteroaryl is substituted or unsubstituted, 5- or 6-membered, monocyclic heteroaryl, wherein 1, 2, 3, or 4 atoms in the heteroaryl ring system are independently oxygen, nitrogen, or sulfur. In certain embodiments, the heteroaryl is substituted or unsubstituted, 9- or 10-membered, bicyclic heteroaryl, wherein 1, 2, 3, or 4 atoms in the heteroaryl ring system are independently oxygen, nitrogen, or sulfur.

[0346] In some embodiments, a heteroaryl group is a 5-10 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-8 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-6 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heteroaryl”). In some embodiments, the 5-6 membered heteroaryl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur. Unless otherwise specified, each instance of a heteroaryl group is independently unsubstituted (an “unsubstituted heteroaryl”) or substituted (a “substituted heteroaryl”) with one or more substituents. In certain embodiments, the heteroaryl group is an unsubstituted 5-14 membered heteroaryl. In certain embodiments, the heteroaryl group is a substituted 5-14 membered heteroaryl.

[0347] Exemplary 5-membered heteroaryl groups containing 1 heteroatom include pyrrolyl, furanyl, and thiophenyl. Exemplary 5-membered heteroaryl groups containing 2 heteroatoms include imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5- membered heteroaryl groups containing 3 heteroatoms include triazolyl, oxadiazolyl, and thiadiazolyl. Exemplary 5-membered heteroaryl groups containing 4 heteroatoms include tetrazolyl. Exemplary 6-membered heteroaryl groups containing 1 heteroatom include pyridinyl. Exemplary 6-membered heteroaryl groups containing 2 heteroatoms include pyridazinyl, pyrimidinyl, and pyrazinyl. Exemplary 6-membered heteroaryl groups containing 3 or 4

[0348] #14695765vl heteroatoms include triazinyl and tetrazinyl, respectively. Exemplary 7-membered heteroaryl groups containing 1 heteroatom include azepinyl, oxepinyl, and thiepinyl. Exemplary 5,6- bicyclic heteroaryl groups include indolyl, isoindolyl, indazolyl, benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, and purinyl. Exemplary 6,6-bicyclic heteroaryl groups include naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl. Exemplary tricyclic heteroaryl groups include phenanthridinyl, dibenzofuranyl, carbazolyl, acridinyl, phenothiazinyl, phenoxazinyl, and phenazinyl.

[0349] The term “unsaturated bond” refers to a double or triple bond.

[0350] The term “unsaturated” or “partially unsaturated” refers to a moiety that includes at least one double or triple bond.

[0351] The term “saturated” or “fully saturated” refers to a moiety that does not contain a double or triple bond, e.g., the moiety only contains single bonds.

[0352] The term “acyl” refers to a group having the general formula -C(=O)RX1, -C(=O)ORX1, -C(=O)-O-C(=O)RX1, -C(=O)SRX1, -C(=O)N(RX1)2, -C(=S)RX1, -C(=S)N(RX1)2, and -C(=S)S(RX1), -C(=NRX1)RX1, -C(=NRX1)ORX1, -C(=NRX1)SRX1, and -C(=NRX1)N(RX1)2, wherein RX1is hydrogen; halogen; substituted or unsubstituted hydroxyl; substituted or unsubstituted thiol; substituted or unsubstituted amino; substituted or unsubstituted acyl, cyclic or acyclic, substituted or unsubstituted, branched or unbranched aliphatic; cyclic or acyclic, substituted or unsubstituted, branched or unbranched heteroaliphatic; cyclic or acyclic, substituted or unsubstituted, branched or unbranched alkyl; cyclic or acyclic, substituted or unsubstituted, branched or unbranched alkenyl; substituted or unsubstituted alkynyl; substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, aliphaticoxy, heteroaliphaticoxy, alkyloxy, heteroalkyloxy, aryloxy, heteroaryloxy, aliphaticthioxy, heteroaliphaticthioxy, alkylthioxy, heteroalkylthioxy, arylthioxy, heteroarylthioxy, mono- or di- aliphaticamino, mono- or di- heteroaliphaticamino, mono- or di- alkylamino, mono- or di- hetero alkylamino, mono- or di-arylamino, or mono- or di-heteroarylamino; or two RX1groups taken together form a 5- to 6-membered heterocyclic ring. Exemplary acyl groups include aldehydes (-CHO), carboxylic acids (-CO2H), ketones, acyl halides, esters, amides, imines, carbonates, carbamates, and ureas. Acyl substituents include, but are not limited to, any of the substituents described herein, that result in the formation of a stable moiety e.g., aliphatic, alkyl, alkenyl, alkynyl, heteroaliphatic, heterocyclic, aryl, heteroaryl, acyl, oxo, imino, thiooxo, cyano, isocyano, amino, azido, nitro,

[0353] #14695765vl hydroxyl, thiol, halo, aliphaticamino, heteroaliphaticamino, alkylamino, heteroalkylamino, arylamino, heteroarylamino, alkylaryl, arylalkyl, aliphaticoxy, heteroaliphaticoxy, alkyloxy, heteroalkyloxy, aryloxy, heteroaryloxy, aliphaticthioxy, heteroaliphaticthioxy, alkylthioxy, heteroalkylthioxy, arylthioxy, heteroarylthioxy, acyloxy, and the like, each of which may or may not be further substituted).

[0354] A “counterion” is a charged group associated with an oppositely charged group in order to maintain electronic neutrality.

[0355] As used herein, the term “salt” refers to any and all salts, and encompasses pharmaceutically acceptable salts. Salts include ionic compounds that result from the neutralization reaction of an acid and a base. A salt is composed of one or more cations (positively charged ions) and one or more anions (negative ions) so that the salt is electrically neutral (without a net charge). Salts of the compounds of the present disclosure include those derived from inorganic and organic acids and bases. Examples of acid addition salts are salts of an amino group formed with inorganic acids, such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid, or with organic acids, such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid or by using other methods known in the art such as ion exchange. Other salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, -toliienesiilfonate, undecanoate, valerate, hippurate, and the like. Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N+(Ci-4 alkyl)4 salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further salts include ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate, and aryl sulfonate.

[0356] As used herein the term “thermal treatment” refers to any method capable of generating heat to induce a chemical reaction or physical process; such methods include but are not limited to, supplying heat using hot-air convection furnaces, magnetic induction, microwave radiation,

[0357] #14695765vl infrared radiation, near-infrared radiation, optionally combined with near- infrared dyes such as but not limited to, cyanines, porphyrine dyes, squaraine dyes, phtalocyanines, squarylium salts, diimonium salts, and dithiolene complexes.

[0358] International Application No. PCT / US2024 / 056301, filed November 15, 2024, and entitled “Poly(meth)acrylimide Materials with Enhanced Thermomechanical Properties,” and U.S. Provisional Patent Application No. 63 / 729,933, filed December 9, 2024, and entitled “High Performance Fiber-Reinforced Composite Materials and Articles,” are incorporated herein by reference in their entirety for all purposes.

[0359] The following disclosure is directed to examples intended to illustrate certain embodiments of the present disclosure related to composite manufacture and analysis. It does not necessarily exemplify the full scope of the disclosure.

[0360] A method of making fiber-reinforced articles is generally described. Such articles may include a poly(meth)acrylimide and / or such method may comprise using NIR dyes to promote curing.

[0361] For embodiments in which a poly(meth)acrylimide resin is employed, the resin may be cured using thermal treatment or actinic radiation or a combination of methods including at least one thermal or actinic radiation mediated step, for example, as set forth but not limited to the methods below:

[0362] 1) Thermal curing (via radiation, convection, conduction, induction, resistance, ultrasonic, and the like) coupled with at least one thermal initiator;

[0363] 2) Photochemical curing (via actinic radiation), optionally coupled with a photoinitiator (which may be beneficial for wavelengths above 200 nm, and omitted for wavelengths less than 200 nm or electron beam radiation);

[0364] 3) A combination of methods 1) and 2).

[0365] NIR active dyes (e.g., cyanine dyes) can also be used to cure poly(meth)acrylimide resins, optionally in addition to methods 1), 2), and / or 3), or used alone. NIR dyes can cure the resin:

[0366] 4) Thermally (via the photothermal effect generated by IR or NIR radiations with or without the presence of dyes within the polymer matrix, when irradiated with NIR radiation, coupled with a thermal initiator);

[0367] 5) Photochemically (via photoredox system using NIR dyes as sensitizers together with an electron accepting salt (initiator) and optionally a reducing agent to restore the catalytic cycle);

[0368] #14695765vl 6) A combination of methods 4) and 5);

[0369] 7) A combination of methods l)-6).

[0370] In some embodiments, subsequent to the curing of a poly(meth)acrylimide resin, the cured resin may be imidized to form the poly(meth)acrylimide.

[0371] In some embodiments, a resin other than a poly(meth)acrylimide resin is cured with the use of NIR active dyes (e.g., cyanine dyes) as described in methods 4)-7) above, non-limiting examples of which include resins that can be cured by heat without needing the inclusion of an initiator (e.g., epoxies, phenolic resins, polyesters, polyurethanes, bismaleimides, polyimides, cyanate esters, silicone resins, polybenzimidazoles, polyphenylenesulfides, polyether ketones, polyether imides, or hybrids and combinations of these resins), resins that cure via thermal radical formation (e.g., polymethacrylates, poly acrylates, polystyrenes, styrene acrylonitriles, polyesters, vinyl esters, other vinyl polymers), and / or resins that can be cured via photo radical and / or cation formation (e.g., polymethacrylates, polyacrylates, polystyrenes, styrene acrylonitriles, polyesters, vinyl polymers, vinyl ethers, vinyl esters, epoxies, lactones). Resins that can be cured via photo radical and / or cation formation can also include, in the resin, a salt, such as a salt described in method 5) above.

[0372] The fiber reinforcement may comprise glass, quartz, carbon, aramid, basalt, ceramic, metal, mineral, plastic / polymer, bio- and / or natural fibers, or a combination thereof. The resin may, after curing, form a binder and / or a foam. The resin may impregnate the fibers and a preimpregnated fiber mat may be formed and / or the resin may be infused in the dry fiber cloth using infusion techniques. To produce the final composite article, standard dry or wet processing techniques can be used, alone or in combination. Such techniques may include hand lay-up, Resin Transfer Molding (RTM), Vacuum Assisted Resin Transfer Molding (VARTM), Filament winding, Braiding, Liquid Molding, including Liquid Compression Molding (LCM), High-Pressure Resin Transfer Molding (HP-RTM), Pultrusion, tape deposition, ribbonizing, additive manufacturing, compression molding, sheet molding compounding, and more.

[0373] Fiber-reinforced polymer composites (FRPs) are widely used in aerospace, automotive, marine, wind energy, sporting goods, and civil infrastructure applications because of their high strength-to-weight ratio and corrosion resistance.

[0374] Conventional thermoset resins (epoxies, polyesters, vinyl esters) require heat curing and long cycle times. Traditional UV-curable resins generally suffer from oxygen inhibition, limited depth of cure, and inferior mechanical properties (especially heat resistance).

[0375] #14695765vl Resin systems that have one or more of the following properties could be desirable: (i) low viscosity suitable for RTM, VARTM, infusion, wet lay-up, filament winding, pultrusion, etc.; (ii) capable of being rapidly cured by actinic radiation, by heat, or by both; and / or (iii) after cure delivers mechanical properties equal to or superior to state-of-the-art aerospace-grade resins (e.g., Tggreater than 180 °C, tensile strength greater than 80 MPa, interlaminar shear strength greater than 60 MPa).

[0376] Some cured and / or imidized poly(meth)acrylimide resins have very high mechanical and / or thermomechanical properties (e.g., Tgabove 200 °C and / or 240 °C) and / or offer enhanced flexibility in terms of functionalization. Some poly(meth)acrylimide resins also have outstanding adhesion to glass and metal substrates, and are compatible with most other resins. Some poly(meth)acrylimide resins thermomechanically outperform many other resins.

[0377] Some embodiments allow manufacturing of high value, high-performance, high temperature fiber reinforced poly(meth)acrylimide composite materials and articles with high process efficiency, i.e. very rapidly and at low cost.

[0378] As noted above, some embodiments allow manufacturing of fiber reinforced composite materials for resins other than poly(meth)acrylimides that are cured using NIR dyes.

[0379] Heat or actinic radiation can be applied to manual or automated composite manufacturing to cure the resin composite in several ways (e.g., B-stage cure, complete cure, gel coat cure, and the like).

[0380] B-stage curing: Heat or actinic radiation emitting devices may be placed after a resin impregnation step (resin bath or other), intended to wet the fiber and partially cure the resin to a tacky state. This step is performed just before the automated lay-up process, such as winding, braiding, or other similar methods. When NIR dyes are employed to promote curing, the actinic radiation may comprise near-infrared radiation.

[0381] Complete curing: Heat or actinic radiation emitting devices may be placed after a resin impregnation step (resin bath or other) and complete cure may be possible. If B-stage curing is used as described previously, then final UV cure can take place after fiber placement. When NIR dyes are employed to promote complete curing, the actinic radiation may comprise nearinfrared radiation.

[0382] Gel coat curing: A heat- or actinic radiation-curable topcoat or gel coat can be applied to provide parts with a scratch-resistant and durable finish. This topcoat can be applied either by spraying or manual brushing onto the fully cured part. When NIR dyes are employed to promote gel coat curing, the actinic radiation may comprise near-infrared radiation.

[0383] #14695765vl In some embodiments, a resin has a composition described as being suitable for a reaction mixture in International Application No. PCT / US2024 / 056301, filed November 15, 2024, and entitled “Poly(meth)acrylimide Materials with Enhanced Thermomechanical Properties,” which is incorporated herein by reference in its entirety for all purposes. In some embodiments, a precursor polymer and / or a poly(meth)acrylimide have a composition as described in International Application No. PCT / US2024 / 056301. In some embodiments, a NIR dye is a near-infrared dye as described in International Application No. PCT / US2024 / 056301. It is also possible for curing, forming a precursor polymer, imidization, and / or foaming to be performed according to a process described in International Application No. PCT / US2024 / 056301.

[0384] Thermal cure using NIR radiation and / or curing with NIR photothermal dyes may allow for curing of thick fiber composites, such as those thicker than 10-15 mm. This may be facilitated by the use of NIR transparent fibers, such as but not limited to, glass, quartz, and / or organic fibers. Some NIR dyes are desirably fully soluble organic molecules that can be homogeneously distributed in the resin composition and / or do not require altering the physical properties of the resin.

[0385] The following examples are intended to illustrate certain embodiments of the present invention, buts does not exemplify the full scope of the invention.

[0386] EXAMPLE 1

[0387] The following example describes fiber-reinforced composites.

[0388] FIG. 3 shows, according to certain embodiments, a photograph of a glass fiber impregnated cloth. The glass fiber cloth was infused with poly(meth)acrylimide precursor resin, photocured using UV electromagnetic radiation, and turned into poly(meth)acrylimide through a thermal process. The glass fiber impregnated cloth has a width of 30 centimeters.

[0389] FIG. 4 shows, according to certain embodiments, a photograph of the results of an ASTM D3359 crosshatch test on adhesion of a poly(meth)acrylimide coating on a glass plate substrate, demonstrating a 5B rating, which represents the maximum adhesion on the ASTM scale. While the poly(meth)acrylimide shows desirable adhesion properties, the observed performance may vary depending on: (i) surface treatment of the glass plate; and / or (ii) the type and / or sizing of fibers used in a fiber-reinforced composite.

[0390] FIG. 5 shows, according to certain embodiments, a photograph of a UV-cured poly(meth)acrylimide glass fiber composite. The composite has a width of 30 centimeters.

[0391] #14695765vl FIG. 6 shows, according to certain embodiments, a UV-cured poly(meth)acrylimde precursor polymer glass fiber composite. The composite has a width of 30 centimeters.

[0392] FIG. 7 shows, according to certain embodiments, a thermally cured carbon fiber poly(meth)acrylimide composite. The composite has a width of 30 centimeters.

[0393] EXAMPLE 2

[0394] The following example describes a UV-curable composite.

[0395] A glass fiber material (Hexcel Style 3733 E-glass with 504 Chrome Sizing) was cut to the required dimensions. A photocurable poly(meth)acrylimide (PMI) resin composition was prepared immediately prior to layup. The viscosity of the resin was measured according to ASTM D2196 (2020) at 25 °C using a rotational viscometer (see FIG. 8, PMI). The tool surface, which was made of glass, was cleaned to remove contaminants and subsequently coated with a suitable release agent to facilitate removal of the cured composite article.

[0396] The UV-curable resin composition was applied to the reinforcement using a brush. The resin was worked into the reinforcement to ensure thorough impregnation of the fiber bundles and to displace entrapped air. Impregnated plies were placed onto the prepared tool surface in accordance with a predetermined ply sequence. The total number of plies was 6. Additional resin was applied as needed to achieve full wet-out and uniform resin distribution. Consolidation of the plies was performed using a hand roller to remove voids and ensure intimate contact between adjacent layers.

[0397] Following layup, a vacuum-bagging step was employed. A peel ply, a perforated release film, and a breather layer were placed over the laminate. A flexible vacuum bag was sealed around the perimeter of the tool, and vacuum was applied to compact the laminate and regulate resin content. The laminate was maintained under vacuum for a duration sufficient to achieve consolidation.

[0398] The consolidated laminate was then subjected to UV radiation to initiate curing of the resin matrix. UV exposure was provided through the vacuum bag assembly. The laminate was irradiated at 405 nm using a LED lamp with an irradiance of 15.5 mW / cm2suitable to activate the photoinitiator system and effect polymerization of the resin. Exposure continued for 25 minutes until the resin reached a fully cured state as determined by Tgmeasurements. The Tgof the composite was measured according to ASTM D7028-07R24 (2024 revision) (see FIG. 9, PMI).

[0399] #14695765vl Upon completion of the curing step, the composite article was removed from the tool. Excess material was trimmed, and the part was then subsequently imidized in a convection oven at temperatures up to 200 °C.

[0400] For testing of tensile properties, the laminate was cut to shape with a water-cooled tile saw. Testing was performed according to ASTM D3039 / D3039M-23 (2023). Results are shown in FIGs. 10-12. FIG. 10 shows, according to certain embodiments, the tensile strength of the PMI composite. FIG. 11 shows, according to certain embodiments, the elongation at break of the PMI composite. FIG. 12 shows, according to certain embodiments, the tensile modulus of the PMI composite.

[0401] EXAMPLE 3

[0402] The following example describes a UV-curable composite prepared by vacuum-assisted resin transfer molding (VARTM).

[0403] A sheet of glass having a substantially planar upper surface was cleaned with isopropyl alcohol and dried to remove particulates and contaminants. A release film or mold-release agent was applied to the glass surface to facilitate subsequent removal of the cured laminate.

[0404] A dry fiber preform was prepared by stacking multiple plies of fiber fabric to achieve the desired laminate thickness and fiber orientation. The fibers used were either E-Glass or S-Glass. For E-Glass, fibers were either plain weave, or arranged to have an orientation of ±45° or of 0 / 90°. The plies were placed directly onto the treated glass surface and manually compacted to ensure intimate contact and to minimize entrapped air. A peel-ply layer was positioned beneath the fiber stack or on its surface, as desired, to allow later removal of consumables and to provide an appropriate surface texture.

[0405] A flow-distribution medium was placed over the upper surface of the fiber preform. A vacuum bag film was then draped over the entire assembly and sealed along the periphery of the glass substrate using a tacky sealant tape to form an airtight enclosure. A resin inlet port and a vacuum outlet port were installed through the vacuum bag at predetermined locations to control infusion and evacuation.

[0406] The enclosed assembly was evacuated using a vacuum pump until a vacuum level of approximately 100 kPa below atmospheric pressure was achieved. The vacuum was held for a predetermined period (e.g., 10-30 minutes) to compact the fiber preform and remove residual air and moisture.

[0407] #14695765vl A UV-curable PMI liquid resin composition was placed in a resin reservoir connected to the inlet port. With full vacuum maintained at the outlet port, the inlet valve was slowly opened, allowing the resin to be drawn into the fiber preform by the pressure differential across the vacuum bag. The resin was permitted to flow through the distribution medium until the fiber stack was fully wetted, as verified visually. After complete wet-out, the inlet valve was closed while maintaining vacuum at the outlet port.

[0408] The impregnated laminate was then subjected to UV radiation to initiate curing of the resin matrix. UV exposure was provided through the vacuum bag assembly. The laminate was irradiated at 405 nm using a LED lamp with an irradiance of 15.5 mW / cm2suitable to activate the photoinitiator system and effect polymerization of the resin. Exposure continued for 25 minutes until the resin reached a fully cured state (as determined by Tgmeasurements).

[0409] Upon completion of the curing step, the vacuum bag, peel ply, and flow-distribution medium were removed, and the cured composite laminate was lifted from the glass substrate. Excess material was trimmed, and the part was then subsequently imidized in a convection oven at temperatures up to 200 °C.

[0410] For testing of tensile properties, short beam shear strength, and glass transition temperature, the laminate was cut to shape with a water-cooled tile saw. Testing was performed according to ASTM D3039 / D3039M-23 (2023) (tensile), ASTM D2344 (2022) (interlaminar short-beam shear strength), and ASTM D7028-07R24 (Tg). Results are shown in FIGs. 13-16. FIG. 13 shows, according to certain embodiments, the tensile strength of a UV-cured E-glass plain weave fiber composite, a UV-cured S-glass plain weave fiber composite, a UV-cured E- glass biaxial fiber ±45° composite, and a UV-cured E-glass biaxial fiber 0 / 90° composite. FIG.

[0411] 14 shows, according to certain embodiments, the elongation at break of a UV-cured E-glass plain weave fiber composite, a UV-cured S-glass plain weave fiber composite, a UV-cured E- glass biaxial fiber ±45° composite, and a UV-cured E-glass biaxial fiber 0 / 90° composite. FIG.

[0412] 15 shows, according to certain embodiments, the tensile modulus of a UV-cured E-glass plain weave fiber composite, a UV-cured S-glass plain weave fiber composite, a UV-cured E-glass biaxial fiber ±45° composite, and a UV-cured E-glass biaxial fiber 0 / 90° composite. FIG. 16 shows, according to certain embodiments, the interlaminar short-beam shear strength of a UV- cured E-glass plain weave fiber composite and a UV-cured S-glass plain weave fiber composite.

[0413] FIG. 17 shows the storage modulus (E’) and tan delta of a plain weave S-glass / PMI and plain weave E-glass / PMI composite. The tan delta peak of the composites corresponds to the glass transition temperature of the composites.

[0414] #14695765vl EXAMPLE 4

[0415] The following example describes a thermally curable composite prepared by vacuum- assisted resin transfer molding (VARTM).

[0416] A sheet of glass having a substantially planar upper surface was cleaned with isopropyl alcohol and dried to remove particulates and contaminants. A release film or mold-release agent was applied to the glass surface to facilitate subsequent removal of the cured laminate.

[0417] A dry fiber preform was prepared by stacking multiple plies of fiber fabric to achieve the desired laminate thickness and fiber orientation. The fibers used were either plain weave E- Glass or plain weave carbon fibers. The plies were placed directly onto the treated glass surface and manually compacted to ensure intimate contact and to minimize entrapped air. A peel-ply layer was positioned beneath the fiber stack or on its surface, as desired, to allow later removal of consumables and to provide an appropriate surface texture.

[0418] A flow-distribution medium was placed over the upper surface of the fiber preform. A vacuum bag film was then draped over the entire assembly and sealed along the periphery of the glass substrate using a tacky sealant tape to form an airtight enclosure. A resin inlet port and a vacuum outlet port were installed through the vacuum bag at predetermined locations to control infusion and evacuation.

[0419] The enclosed assembly was evacuated using a vacuum pump until a vacuum level of approximately 100 kPa below atmospheric pressure was achieved. The vacuum was held for a predetermined period (e.g., 10-30 minutes) to compact the fiber preform and remove residual air and moisture.

[0420] A thermally curable PMI liquid resin composition was placed in a resin reservoir connected to the inlet port. With full vacuum maintained at the outlet port, the inlet valve was slowly opened, allowing the resin to be drawn into the fiber preform by the pressure differential across the vacuum bag. The resin was permitted to flow through the distribution medium until the fiber stack was fully wetted, as verified visually. After complete wet-out, the inlet valve was closed while maintaining vacuum at the outlet port.

[0421] The impregnated laminate was then subjected to thermal curing either in a convection oven for both glass-fibers and carbon fibers, or under NIR radiation: for carbon fibers, the laminate was exposed directly to NIR radiation whereupon the photothermal effect of the carbon fiber provided controlled heat generation to initiate and complete the cure. For glass fiber, NIR dyes were added to the PMI formulation to generate the photothermal effect. The magnitude of

[0422] #14695765vl the photothermal effect was controlled by varying the irradiance of the light source. Typical curing temperatures were 50-140 °C for 30-180 minutes depending on the thermal initiator employed.

[0423] Upon completion of the curing step, the vacuum bag, peel ply, and flow-distribution medium were removed, and the cured composite laminate was lifted from the glass substrate. Excess material was trimmed, and the part was then subsequently imidized at temperatures up to 200 °C, either in a convection oven, or by using the photo thermal effect of carbon fiber or NIR dyes (FIG 18). FIG. 18 shows, according to certain embodiments, the photothermal effect of a carbon fiber composite, a glass fiber composite, and a glass fiber composite impregnated with resin with 0.5 wt.% NIR active dye upon exposure to NIR radiation (810 nm, 1.2 W / cm2).

[0424] For testing of tensile properties, short beam shear strength, and glass transition temperature, the laminate was cut to shape with a water-cooled tile saw. Testing was performed according to ASTM D3039 / D3039M-23 (2023) (tensile), ASTM D2344 (2022) (interlaminar short-beam shear strength), and ASTM D7028-07R24 (Tg). Results are shown in FIG. 13-16. FIG. 13 shows, according to certain embodiments, the tensile strength of a thermally cured plain weave E-glass fiber composite and a thermally cured plain weave carbon fiber composite. FIG.

[0425] 14 shows, according to certain embodiments, the elongation at break of a thermally cured plain weave E-glass fiber composite and a thermally cured plain weave carbon fiber composite. FIG.

[0426] 15 shows, according to certain embodiments, the tensile modulus of a thermally cured plain weave E-glass fiber composite and a thermally cured plain weave carbon fiber composite. FIG.

[0427] 16 shows, according to certain embodiments, the interlaminar short-beam shear strength of a thermally cured plain weave E-glass fiber composite, a thermally cured plain weave carbon fiber composite, and a NIR cured E-glass fiber composite.

[0428] COMPARATIVE EXAMPLE 1

[0429] Photocurable resins for glass fiber composites of the Raylok™ series (Allnex) were used to impregnate glass fibers according to the method described in Example 1. The viscosity of the resins were measured according to ASTM D2196 (2020) at 25 °C using a rotational viscometer (see FIG. 8, Raylok™ 1100, 1101, and 1102). As shown in FIG. 8, the PMI resin has a substantially lower viscosity than the Raylok™ series.

[0430] The laminate was cured following Allnex’ s technical datasheet recommendations. The Tgof the composite was measured according to ASTM D7028-07R24 (2024 revision) (see FIG.

[0431] #14695765vl 9, Raylok™ 1100, 1101, and 1102). As shown in FIG. 9, the PMI composite has a substantially higher Tgthan the Raylok™ series composites.

[0432] For testing of tensile properties, the laminate was cut to shape with a water-cooled tile saw. Testing was performed according to ASTM D3039 / D3039M-23 (2023). Results are shown in FIGs. 10-12. FIG. 10 shows, according to certain embodiments, the tensile strength of the Raylok™ series composites. As shown in FIG. 10, the PMI composite has a greater tensile strength than the Raylok™ series composites. FIG. 11 shows, according to certain embodiments, the elongation at break of the Raylok™ series composites. As shown in FIG. 11, the PMI composite has a greater elongation at break than the Raylok™ 1100 and 1101 composites. FIG. 12 shows, according to certain embodiments, the tensile modulus of the Raylok™ series composites. As shown in FIG. 12, the PMI composite has a greater tensile strength than the Raylok™ series composites.

[0433] COMPARATIVE EXAMPLE 2

[0434] The epoxy system Epon™ 828 with curing agent Lindride 46 was used to impregnate glass fibers according to the method described in Example 1. The viscosity of the resin was measured according to ASTM D2196 (2020) at 25 °C using a rotational viscometer (see FIG. 8, Epon™ 828 / Anhydride). As shown in FIG. 8, the PMI resin has a substantially lower viscosity than the Epon™ 828 / Anhydride resin.

[0435] Thermal curing was performed in a convection oven according to technical datasheet recommendations. The Tgof the composite was measured according to ASTM D7028-07R24 (2024 revision) (see FIG. 9, Epon™ 828 / Anhydride). As shown in FIG. 9, the PMI composite has a substantially higher Tgthan the Epon™ 828 / Anhydride composite.

[0436] For testing of tensile properties, the laminate was cut to shape with a water-cooled tile saw. Tensile testing was performed according to ASTM D3039 / D3039M-23 (2023). Results are displayed in FIGs. 10-12. FIG. 10 shows, according to certain embodiments, the tensile strength of the Epon™ 828 / Anhydride composite. As shown in FIG. 10, the PMI composite has a greater tensile strength than the Epon™ 828 / Anhydride composite. FIG. 11 shows, according to certain embodiments, the elongation at break of the Epon™ 828 / Anhydride composite. FIG. 12 shows, according to certain embodiments, the tensile modulus of the Epon™ 828 / Anhydride composite. As shown in FIG. 12, the PMI composite has a greater tensile strength than the Epon™ 828 / Anhydride composite.

[0437] #14695765vl Statement of Embodiments

[0438] The following statements describe embodiments of the present disclosure according to the foregoing description and examples.

[0439] In a first statement of embodiments, a method is described, the method comprising: infusing a polymer resin into a plurality of fibers; curing the polymer resin to form a precursor polymer; and imidizing the precursor polymer to form a poly(meth)acrylimide.

[0440] In a second statement of embodiments, a method is described, the method comprising: infusing a polymer resin into a plurality of fibers, wherein the polymer resin comprises a NIR dye; and curing the polymer resin by irradiating the polymer resin with near-infrared light to form a precursor polymer to a poly(meth)acrylimide, an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, an acrylate, and / or a methacrylate.

[0441] In a third statement of the embodiments, a method as in the first statement is described, wherein curing the polymer resin comprises heating the polymer resin.

[0442] In a fourth statement of embodiments, a method as in the first statement or the third statement is described, wherein curing the polymer resin comprises exposing the polymer resin to actinic radiation.

[0443] In a fifth statement of embodiments, a method as in the fourth statement is describe, wherein the actinic radiation comprises UV light.

[0444] In a sixth statement of embodiments, a method as in any preceding statement is described, wherein curing the polymer resin comprises performing B-stage curing, complete curing, and / or gel coat curing.

[0445] In a seventh statement of embodiments, a method as in any preceding statement is described, wherein the polymer resin comprises a photoinitiator.

[0446] In an eighth statement of embodiments, a method as in any preceding statement is described, wherein the polymer resin comprises a NIR dye.

[0447] In a ninth statement of embodiments, a method as in any preceding statement is described, wherein infusing the polymer resin into the plurality of fibers comprises performing a hand lay-up process, a resin transfer molding process, a vacuum assisted resin transfer molding process, a filament winding process, braiding, a liquid molding process, a liquid compression molding process, a high-pressure resin transfer molding process, pultrusion, a tape deposition process, ribbonizing, an additive manufacturing process, a compression molding process, and / or a sheet molding compounding process.

[0448] #14695765vl In a tenth statement of embodiments, a method as in any preceding statement is described, wherein the method further comprises imidizing the precursor polymer to form the poly(meth)acrylimide.

[0449] In an eleventh statement of embodiments, a method as in any preceding statement is described, wherein imidizing the precursor polymer comprises heating the polymer resin.

[0450] In a twelfth statement of embodiments, a method as in any preceding statement is described, wherein imidizing the precursor polymer comprises irradiating the polymer resin with actinic radiation.

[0451] In a thirteenth statement of embodiments, a method as in any preceding statement is described, wherein imidizing the precursor polymer causes the precursor polymer to undergo foaming.

[0452] In a fourteenth statement of embodiments, a fiber-reinforced composite is described, the fiber-reinforced composite comprising: a plurality of fibers; and a poly(meth)acrylimide resin.

[0453] In a fifteenth statement of embodiments, a method or fiber-reinforced composite as in any preceding statement is described, wherein the plurality of fibers comprises glass fibers, carbon fibers, aramid fibers, metal fibers, plastic fibers, and / or natural fibers.

[0454] In a sixteenth statement of embodiments, a method or fiber-reinforced composite as in any preceding statement is described, wherein the poly(meth)acrylimide is foamed.

[0455] In a seventeenth statement of embodiments, a method or fiber-reinforced composite as in any one of the first statement to the sixteenth statement is described, wherein the poly(meth)acrylimide is unfoamed.

[0456] It should be understood that the subject matter defined in the appended claims was not necessarily limited to the specific implementations described above. The specific implementations described above are disclosed as examples only. While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the teachings of the present invention is / are used. Those

[0457] #14695765vl skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods, if such features, systems, articles, materials, and / or methods are not mutually inconsistent, is included within the scope of the present invention.

[0458] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0459] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0460] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0461] #14695765vl As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0462] As used herein, “wt%” is an abbreviation of weight percentage. As used herein, “at%” is an abbreviation of atomic percentage.

[0463] Some embodiments may be embodied as a method, of which various examples have been described. The acts performed as part of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include different (e.g., more or less) acts than those that are described, and / or that may involve performing some acts simultaneously, even though the acts are shown as being performed sequentially in the embodiments specifically described above.

[0464] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0465] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed

[0466] #14695765vl 1 transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent

[0467] 2 Examining Procedures, Section 2111.03.

[0468] #14695765vl

Claims

CLAIMSWhat is claimed is:

1. A fiber-reinforced composite, comprising: a plurality of fibers; and a poly(meth)acrylimide impregnated within the plurality of fibers.

2. A method, comprising: impregnating a polymer resin into a plurality of fibers; curing the polymer resin to form a precursor polymer; and imidizing the precursor polymer to form a poly(meth)acrylimide.

3. A method, comprising: impregnating a polymer resin into a plurality of fibers, wherein the polymer resin comprises a near-infrared (NIR) dye; and curing the polymer resin by irradiating the polymer resin with NIR electromagnetic radiation to form a precursor polymer to a poly(meth)acrylimide, an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, a bismaleimide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylenesulfide, a polyether ketone, a polyether imide, a polystyrene, a vinyl ether, a lactone, a blend of two or more of the foregoing, and / or a copolymer of two or more of the foregoing.

4. The method of claim 3, wherein the polymer resin further comprises a precursor to a polyacrylate and / or a polymethacrylate.

5. The method of claim 3 or 4, wherein the polymer resin further comprises a salt initiator.#14695765vl6. The method of any one of the preceding claims, wherein curing the polymer resin comprises heating the polymer resin.

7. The method of any one of the preceding claims, wherein the polymer resin comprises a thermal initiator.

8. The method of claim 7, wherein the thermal initiator comprises an organic peroxide, an azo-compound, a persulfate, a nitroxide-generating species, and / or an organosulfur radical source.

9. The method of claim 7 or 8, wherein the thermal initiator is one or more of tertamyl peroxybenzoate, 4,4-azobis(4-cyanovaleric acid), 1,1’- azobis(cyclohexanecarbonitrile), 2,2’-azobisisobutyronitrile, benzoyl peroxide, 2,2- bis(tert-butylperoxy)butane, l,l-bis(tert-butylperoxy)cyclohexane, 2,5-bis(tert- butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, bis(l-(tert-butylperoxy)-l-methylethyl)benzene, l,l-bis(tert-butylperoxy)-3,3,5- trimethylcyclohexane, tert-butyl hydroperoxide, tert-butyl peracetate, tert-butyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxy isopropyl carbonate, cumene hydroperoxide, cyclohexanone peroxide, dicumyl peroxide, lauroyl peroxide, 2,4-pentanedione peroxide, peracetic acid, and / or potassium persulfate.

10. The method of any one of claims 2 or 6-9, wherein curing the polymer resin comprises exposing the polymer resin to actinic radiation.

11. The method of claim 10, wherein the actinic radiation comprises ultraviolet (UV) electromagnetic radiation.

12. The method of any one of the preceding claims, wherein curing the polymer resin comprises performing B-stage curing, complete curing, and / or gel coat curing.#14695765vl13. The method of any one of the preceding claims, wherein the polymer resin comprises a photoinitiator.

14. The method of claim 13, wherein the photoinitiator comprises a Type I photoinitiator and / or a Type II photoinitiator.

15. The method of claim 13 or 14, wherein the photoinitiator comprises a benzoin ether, a benzil ketal, an a-dialkoxy-acetophenone, an a-hydroxy-alkylphenone, an a- amino alkylphenone, an acyl phosphine oxide, a benzophenone, a thioxanthone, and / or a metallocene.

16. The method of any one of claims 13-15, wherein the photoinitiator comprises acetophenone, anisoin, anthraquinone, anthraquinone-2-sulfonic acid, benzene tricarbonylchromium, benzil, benzoin, benzoin ethyl ether, benzoin methyl ether, benzophenone, 1 -hydroxycyclohexyl phenyl ketone, 3, 3’, 4, d’benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2- (dimethylamino)-4’-morpholinobutyrophenone, 4,4’-bis(diethylamino)benzophenone, 4,4’-bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthene-9-one, (cumene)cyclopentadienyl iron(ii) hexafluorophosphate, dibenzosuberenone, 2,2- diethoxyacetophenone, 4,4’ -dihydroxybenzophenone, 2,2-dimethoxy-2- phenylacetophenone, 4-(dimethylamino)benzophenone, 4,4’ -dimethylbenzil, 2,5- dimethylbenzophenone, 3,4-dimethylbenzophenone, diphenyl(2,4,6- trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methylpropiophenone, 4’- ethoxyacetophenone, 2-ethylanthraquinone, ferrocene, 3 ’-hydroxy acetophenone, 4’- hydroxyacetophenone, 3-hydroxybenzophenone, 4-hydroxybenzophenone, 1- hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2- methylbenzophenone, 3 -methylbenzophenone, methylbenzoylformate, 2-methyl-4’- (methylthio)-2-morpholinopropiophenone, phenanthrenequinone, 4’- phenoxyacetophenone, thioxanthene-9-one, triarylsulfonium hexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, bis(2,4,6-trimethylbenzoyl)- phenylphosphineoxide, 2,4,6-trimethylbenzoylphenyl phosphinate, bis(2,6-#14695765vldimeth()xybenzoyl)-2,4,4-tri methyl pentyl phosphine oxide, diphenyl (2,4,6- trimethylbenzoyl)phosphine oxide, alpha- hydroxycyclohexyl phenyl ketone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methy|propionyl)benzyl)phenyl-2-methy|propan-l-one,2-hydroxy-2-methyl-l- phenylpropanone,2-hydroxy-2-methyl-l-(4- isopropylphenyl)propanone,oligo(2-hydroxy-2-methyl-l-(4-(l- methylvinyl)phenyl)propanone, 2-hydroxy-2-methyl- 1 -(4-dodecylphenyl)propanone,2- hydroxy-2-methyl-l-[(2-hydroxyethoxy)pheny]]propanone, benzophenone, substituted benzophenones, and mixtures of any two or more thereof.

17. The method of any one of claims 2 or 6-16, wherein the polymer resin comprises a NIR dye.

18. The method of claim 17, wherein the polymer resin further comprises a salt initiator and curing the polymer resin to form the polymer precursor comprises exposing the polymer resin to NIR electromagnetic radiation.

19. The method of any one of the preceding claims, wherein curing the polymer resin comprises partial curing.

20. The method of any one of the preceding claims, wherein the method comprises performing a hand lay-up process, a resin transfer molding process, a vacuum assisted resin transfer molding process, a filament winding process, braiding, a liquid molding process, a liquid compression molding process, a high-pressure resin transfer molding process, pultrusion, a tape deposition process, ribbonizing, an additive manufacturing process, a compression molding process, and / or a sheet molding compounding process.

21. The method of any one of claims 3-20, wherein curing the polymer resin comprises at least partially imidizing the precursor polymer.

22. The method of any one of claims 3-21, further comprising imidizing the precursor polymer to form the poly(meth)acrylimide.#14695765vl23. The method of any one of claims 2 or 21-22, wherein imidizing the precursor polymer comprises heating the polymer resin.

24. The method of any one of claims 2 or 21-23, wherein imidizing the precursor polymer comprises irradiating the polymer resin with actinic radiation.

25. The method of any one of claims 2 or 21-24, wherein imidizing the precursor polymer comprises irradiating the polymer resin with NIR and / or infrared (IR) radiation.

26. The method of any one of claims 2 or 21-25, wherein imidizing the precursor polymer comprises partial imidization.

27. The method of any one of claims 2 or 21-26, wherein imidizing the precursor polymer causes the precursor polymer to undergo foaming.

28. The method of any one of claims 2 or 21-27, wherein imidizing the precursor polymer comprises partial foaming.

29. The method of any one of the preceding claims, wherein the polymer resin has a viscosity of at least 10 cPs at 25 °C.

30. The method of any one of the preceding claims, wherein the precursor polymer has a viscosity of at least 50 cPs at 25 °C.

31. The method of any one of the preceding claims, wherein the method produces a fiber-reinforced composite.

32. A method, comprising: providing a fiber-reinforced composite comprising a precursor polymer to a poly(meth)acrylimide, a photothermal agent, and a plurality of fibers; and#14695765vlimidizing the precursor polymer by irradiating the fiber-reinforced composite with NIR and / or IR electromagnetic radiation.

33. The method of claim 32, wherein the photothermal agent comprises a plasmonic nanostructure, a semiconductor nanomaterial, a metal oxide , a carbon-based NIR absorber, a two-dimensional metal carbide and / or nitride, black phosphorus, and / or a conjugated polymer.

34. The method or fiber-reinforced composite of any one of the preceding claims, wherein the plurality of fibers comprise inorganic fibers and / or organic fibers.

35. The method or fiber-reinforced composite of any one of the preceding claims, wherein the plurality of fibers comprises glass fibers, quartz fibers, carbon fibers, aramid fibers, metal fibers, ceramic fibers, mineral fibers, basalt fibers, plastic fibers, and / or natural fibers.

36. The method or fiber-reinforced composite of any one of the preceding claims, wherein the plurality of fibers comprises glass fibers.

37. The method or fiber-reinforced composite of any one of the preceding claims, wherein the plurality of fibers comprises carbon fibers.

38. The method of any one of claims 2 or 22-37, wherein the plurality of fibers comprises carbon fibers and imidizing the precursor polymer comprises irradiating the polymer resin with NIR and / or IR electromagnetic radiation.

39. The method of claim 38, further comprising irradiating the carbon fibers with NIR and / or IR electromagnetic radiation, wherein the irradiation of the carbon fibers causes the carbon fibers to generate heat that causes imidization of the precursor polymer via a photothermal effect.#14695765vl40. The method or fiber-reinforced composite of any one of the preceding claims, wherein the poly(meth)acrylimide is foamed.

41. The method or fiber-reinforced composite of any one of claims 1-39, wherein the poly(meth)acrylimide is unfoamed.

42. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has an axial compressive strength of at least 500 MPa.

43. The method of fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a transverse compressive strength of at least 50 MPa.

44. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has an interlaminar short-bream shear strength of at least 10 MPa.

45. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a tensile strength of at least 50 MPa.

46. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a tensile modulus of at least 5 GPa.

47. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has an elongation at break of at least 0.5%.

48. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a Mode I toughness of at least 150 J / m2.#14695765vl49. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a creep strain of less than or equal to 2% over 1,000 hours.

50. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has an impact strength of at least 5 J.

51. The method or fiber-reinforced composite of any one of the preceding claims, wherein the fiber-reinforced composite has a glass transition temperature of greater than or equal to 100 °C.

52. The fiber-reinforced composite of any one of the preceding claims, further comprising one or more of an epoxy, a polyurethane, styrene acrylonitrile, a polyester, a vinyl ester, a phenolic, a bismaleimide, a polyimide, a cyanate ester, a silicone resin, a polybenzimidazole, a polyphenylenesulfide, a polyether ketone, a polyether imide, a polyacrylate, a polymethacrylate, a polystyrene, a vinyl ether, a lactone, a blend of two or more of the foregoing, and / or a copolymer of two or more of the foregoing.#14695765vl

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