High temperature composites and methods for preparing high temperature composites - Patents.com

Abstract

A method for making a carbon-carbon composite, a carbon-ceramic matrix composite or a carbon-silica composite, comprising melt processing a resin comprising polyaryletherketone (PAEK) and at least one reinforcing additive to produce a precursor part, pyrolyzing the precursor part to produce a pyrolyzed part, injecting a liquid second resin into the pyrolyzed part to produce an infused part, and pyrolyzing the infused part, wherein the temperature in the chamber is increased one or more times during the pyrolysis at a rate of 1° C. / hr to about 20° C. / hr, and optionally the pyrolysis is maintained at one or more temperatures for a period of time. Other methods include processing a resin comprising aligned reinforcing additive and PAEK to produce aligned reinforcing additive PAEK, aligned 1-2 dimensional flake material or aligned 1-2 dimensional platelet material to produce a fabric, prepreg or tape comprising aligned reinforcing additive and impregnated PAEK. Other methods include impregnating a continuous fiber tape or fabric with a resin containing PAEK and at least one reinforcing additive, or co-weaving a continuous fiber or fabric with PAEK fibers containing PAEK and at least one reinforcing additive.

Description

[Technical field]

[0001] The present invention relates to high temperature composites such as carbon-carbon composites, carbon-ceramic matrix composites and carbon-silica composites. The present invention also relates to methods for preparing high temperature composites such as carbon-carbon composites, carbon-ceramic matrix composites and carbon-silica composites. [Background technology]

[0002] High temperature composites such as carbon-carbon composites, carbon-ceramic matrix composites, and carbon-silica composites can be useful in areas such as hypersonics, solid / liquid rocket propulsion, and other defense / aerospace applications where very high temperature properties are required. Industrial applications can include metal and glass processing, and concentrated solar power.

[0003] High temperature composite materials, including carbon composites, carbon ceramic matrix composites, and carbon silica composites, have traditionally been fabricated utilizing thermosetting resins such as pitch or phenolic resins (e.g., Hexion Durite SC1008) or epoxies. Precursor parts utilizing these thermosetting composites are fabricated by "hand layup," which requires significant manual labor to press the thermosetting prepregs. This manual labor also introduces human error and reduced quality in the precursor parts, in addition to the time and expense of such labor. Thermoplastic composite materials have the advantage that they can be processed by automated methods, including automated tape placement and 3D printing. Thermoplastic tapes have an additional advantage over thermosetting prepregs in that they do not typically require refrigerated shipping and storage.

[0004] Pyrolysis processes (heat treatments) can be used to produce carbon-carbon composites, carbon-ceramic matrix composites, and carbon-silica composites. Pyrolysis can be carried out to preserve the carbon elements while removing volatiles and / or non-carbon organic elements in the composite (such as in a polymer matrix).

[0005] However, the pyrolysis step can sometimes take hundreds of hours, with additional days for graphitization. The process is then repeated several times, resulting in long lead times for the part to be completed. Each additional reinjection and pyrolysis cycle is labor intensive and time consuming. Furthermore, with each cycle, there is a possibility that defects or imperfections may result in an unacceptable final object. It is therefore desirable to reduce the number of cycles required to achieve a fully dense part. A higher char yield allows this process to be shortened, since the part is closer to being completely solid after the first pyrolysis cycle, thereby reducing the number of cycles required. Typically, only phenolic resin-based solutions can provide char yields of 50-70%. Many other (non-PAEK) thermoplastic solutions provide char yields of less than 65%.

[0006] Among other defects to be avoided during the pyrolysis process are dimensional changes of the pyrolyzed parts, in particular the expansion of the parts and / or cracks appearing inside the parts. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US 10,669,659 Summary of the Invention [Problem to be solved by the invention]

[0008] The invention described herein, utilizing polyaryletherketones (PAEKs) and particularly polyetherketoneketones (PEKKs), unexpectedly overcomes these problems. [Means for solving the problem]

[0009] PAEKs, including PEKK, are high performance semi-crystalline polymers with high melting points, extremely high thermal properties, exceptional chemical and flame resistance, and high modulus and strength. By following embodiments of the present invention, it is possible to use thermoplastics to make carbon-carbon, carbon-ceramic matrix and carbon-silica composites. Thermoplastics allow for the preparation of precursor parts by automated methods, which reduces time and cost while improving quality and have unexpectedly high char yields, such as char yields of 70%-80%, up to 85%, up to 90% and even up to 95% or more. Pyrolysis cycles can be speeded up as PAEK materials exhibit a single decomposition point, which alleviates the need for long hold cycles at multiple temperatures often observed with thermosets. The surprisingly high char yields also allow for fewer pyrolysis / infusion steps than other methods, which saves days and even weeks of production time. In certain embodiments, carbon-carbon composites, carbon-ceramic matrix composites, and carbon-silica composites can be made with total processing times of less than about 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, 100 hours, 110 hours, 120 hours, 130 hours, 140 hours, 150 hours, 160 hours, 170 hours, 180 hours, 190 hours, 200 hours, or any range between the specified values.

[0010] Applicants have also surprisingly discovered that, in accordance with embodiments of the present invention, it is possible to utilize precursors to carbon-carbon, carbon-ceramic matrix and carbon-silica composites that combine the advantages of easy processability, high char yields and high mechanical performance.

[0011] Applicants have also surprisingly discovered that in some embodiments it is possible to utilize precursors to carbon-carbon, carbon-ceramic matrix and carbon-silica composites that combine the advantages of the high mechanical performance of PAEK polymers with the high char yield and low dimensional change of the pyrolyzed parts.

[0012] The present invention is directed to a method for making a high temperature composite, which is a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite, comprising the steps of: a. making a precursor part from a resin comprising polyaryletherketone (PAEK) and at least one toughening additive; b. pyrolyzing the precursor part to form a pyrolyzed part; c. injecting a liquid second resin into the pyrolyzed part to form an infused part; d. pyrolyzing the infused part to form a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite; and e. optionally repeating steps c. through d. one or more times. During said pyrolysis, the temperature in the chamber is increased one or more times at a rate of between 1° C. / hour and about 20° C. / hour, and optionally maintained at one or more temperatures for a period of time.

[0013] In one embodiment of the invention, the PAEK comprises one or more of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketone-poly(etherdiphenyletherketone) (PEEK-PEDEK), polyetherketone (PEK) and polyetherketoneetherketoneketone (PEKEKK), preferably PEKK.

[0014] In one embodiment, the PAEK comprises a polyetherketoneketone.

[0015] In one embodiment, the polyetherketoneketone has a T:I isomer ratio of from 50:50 to 78:22, and preferably from 55:45 to 75:25.

[0016] In one embodiment of the present invention, the temperature within the chamber is increased to a peak temperature of about 1000° C. or greater during pyrolysis.

[0017] In one embodiment of the present invention, the liquid second resin comprises one or more of pitch, benzoxazine, furfural, polyester, vinyl ester, acrylic and phenolic resins, preferably pitch and / or phenolic resin.

[0018] In one embodiment of the present invention, the precursor part is made by melt processing a resin including polyaryletherketone (PAEK) and at least one toughening additive, which may include one or more of injection molding, extrusion, rotational molding, compression molding, pultrusion, filament winding, and fused filament manufacturing printing.

[0019] In an embodiment of the invention, the reinforcing additive may include one or more of a carbon-based additive, a chopped fiber, an inorganic additive, or a mixture thereof. The reinforcing additive may include a carbon-based additive that is one or more of a carbon fiber, a carbon nanotube, a graphite, a graphene, a carbon whisker, a fullerene, a carbon black, a carbon flake, a buckyball, and a mixture thereof. The reinforcing additive may include a chopped fiber that is one or more of a carbon, a glass, a silica, a boron, a natural fiber, a polymer fiber, and a mixture thereof. The reinforcing additive may be, inter alia, a chopped carbon fiber or a chopped glass fiber. The reinforcing additive may include an inorganic additive that is one or more of a carbide, a silicide, a boride, or a nitride of group IV, group V, or group VI, and / or a ceramic whisker. The precursor part may include a dispersant that is an organosilicate, an organozirconate, an organoaluminate, or an organotitanate.

[0020] The present invention is also directed to an embodiment whereby the precursor part of step a. is made by a1) impregnating a continuous fiber tape or cloth with a resin comprising polyaryletherketone (PAEK) and at least one reinforcing additive to make a filled PAEK tape or cloth, or co-weaving the continuous fiber or cloth with a PAEK fiber comprising PAEK and at least one reinforcing additive to make a filled co-woven PAEK fiber or cloth, and a2) processing the filled PAEK tape or cloth or the co-woven PAEK fiber or cloth by one or more of the following methods: hand layup, automated tape placement, 3D printing, filament winding, needle punching and other methods of Z-axis consolidation followed by one or more of compression molding, vacuum bag consolidation, autoclave consolidation and in situ consolidation to make the precursor part. The continuous fiber tape or cloth can comprise carbon fiber or glass fiber.

[0021] In another embodiment, the precursor part of step a. is made by a1) processing a resin comprising aligned toughening additive and polyaryletherketone (PAEK) to produce aligned toughening additive PAEK, aligned 1-2D flake material or aligned 1-2D platelet material to produce fabric, prepreg or tape comprising aligned toughening additive and impregnated PAEK, and a2) processing the PAEK tape, prepreg or fabric to produce the precursor part by one or more of the following methods: hand layup, automated tape placement, 3D printing, filament winding, needle punch and other methods of Z-axis consolidation followed by one or more of compression molding, vacuum bag consolidation, autoclave consolidation and in situ consolidation. The toughening additive can be aligned by shear from melt processing. The aligned reinforcing additive can be made by stretching a unidirectional tape until the fibers in the aligned reinforcing additive are broken, subjecting the fibers in the aligned reinforcing additive to a fluid flow to align the fibers, or subjecting the fibers in the aligned reinforcing additive to an electromagnetic field to align the fibers.

[0022] The invention further relates to carbon-carbon, carbon-ceramic matrix or carbon-silica composites made by the methods described and claimed herein. [Brief description of the drawings]

[0023] [Figure 1] 1 is a photograph showing a PEKK sample containing 40% chopped carbon fiber after first pyrolysis with a char yield of 84%. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Embodiments of the present disclosure relate to methods for preparing high temperature composites, such as carbon-carbon, carbon-ceramic matrix and carbon-silica composites. Embodiments of the present disclosure also relate to carbon-carbon, carbon-ceramic matrix and carbon-silica composites made by the disclosed methods.

[0025] As used herein, the term "about" means ±10% of the specified value. By way of example only, at least "about 50 percent" can include at least 45 percent to at least 55 percent (and inclusive).

[0026] The word "comprising" is used consistent with its open-ended meaning, i.e., meaning that a given product or process can optionally have additional features or elements other than those explicitly recited. Even when an embodiment is described with the phrase "comprising," it is understood that other similar embodiments described in terms of "consisting of" and / or "consisting essentially of" are also contemplated and within the scope of the present disclosure.

[0027] As used herein, the term "aligned" means that greater than 75% of the objects have at least one of their major axes oriented in the same direction (±5°) as measured using an image from an optical microscope of a cross-section of the composite.

[0028] As used herein, the term "char yield" refers to the residual carbon content as measured by the mass remaining after pyrolysis, and can be determined as described in the Examples herein.

[0029] As used herein, in the context of composites, the term "% solid" refers to the percent (%) of density of a pyrolyzed part compared to a theoretically fully dense part containing no pores or voids. The density of a fully dense part can be calculated by the formula for a mixture of matrix material (carbon or ceramic) and fiber material (glass or carbon). D = d1a + d2 (1-a) In the above formula, D = density of fully dense parts d1 = density of fiber material (glass or carbon) a = mass fraction of fiber material (glass or carbon) d2=density of the matrix material (carbon or ceramic). The density of a pyrolyzed part can be experimentally determined by dividing its mass by its volume.

[0030] As used herein, the term "composite" refers to a material that includes at least two different and / or separate components. For example, and without limitation, a carbon-carbon composite can include a carbon matrix (e.g., graphite-based) that includes carbon fibers. A carbon ceramic matrix composite can include a ceramic matrix (e.g., SiC) that includes carbon. A carbon silica composite can include a carbon (usually graphite-based) matrix that includes glass / silica fibers.

[0031] As used herein, the term "high temperature," when used in reference to high temperature composites, means and refers to temperatures of about 1000° C. or greater, at which the composite may be used without deleterious decomposition.

[0032] As used herein, the term "pyrolyzing" refers to the application of heat to effect a chemical change in a material, causing the volatilization removal of some, substantially all, or all non-carbon or non-inorganic elements of the material. In the present invention, the chemical change of the precursor generally occurs at a temperature of at least 250°C, particularly at least 400°C.

[0033] As used herein, the term "infusion" (or "infusing") means the permeation of a matrix with a liquid resin, which can fill voids or pores.

[0034] As used herein, the term "chopped" refers to fibers that are not continuous and have a length of less than about 20 mm, preferably less than about 15 mm, preferably less than about 10 mm, and most preferably less than about 5 mm.

[0035] As used herein, the term "polyaryletherketone", known by its acronym "PAEK", refers to a polymer having the following formula: (-Ar-X-) and (-Ar 1 -Y-) (In the formula, - Ar and Ar 1 each represents a divalent aromatic radical, - Ar and Ar 1 may preferably be selected from 1,3-phenylene, 1,4-phenylene, 1,1′-biphenylene divalent in the 3,3′ positions, 1,1′-biphenyl divalent in the 3,4′ positions, 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene, X represents an electron-withdrawing group, which may preferably be chosen from carbonyl and sulfonyl groups, - Y is an oxygen atom, a sulfur atom, or -(CH 2 )- and isopropylidene. In these units X and Y, at least 50%, preferably at least 70% and more particularly at least 80% of the X groups are carbonyl groups and at least 50%, preferably at least 70% and more particularly at least 80% of the Y groups represent oxygen atoms.

[0036] According to a preferred embodiment, 100% of the X groups may represent a carbonyl group and 100% of the Y groups may represent an oxygen atom.

[0037] Advantageously, the PAEK comprises: - polyetherketoneketone, also known as PEKK, comprising one or more repeat units of the formula: -Ph-O-Ph-C(O)-Ph-C(O)-; - polyetheretherketone, also known as PEEK, comprising one or more repeat units of the formula: -Ph-O-Ph-O-Ph-C(O)-; - polyetherketone, also known as PEK, which contains one or more repeat units of the formula: -Ph-O-Ph-C(O)-; - polyetheretherketoneketone, also known as PEEKK, comprising one or more repeat units of the formula: -Ph-O-Ph-O-Ph-C(O)-Ph-C(O)-; - polyetheretheretherketone, also known as PEEEK, comprising one or more repeat units of the formula: -Ph-O-Ph-O-Ph-O-Ph-C(O)- - polyether diphenyl ether ketone, also known as PEDEK, comprising one or more repeat units of the formula: -Ph-O-Ph-Ph-O-Ph-C(O)- - and mixtures thereof; and - a copolymer comprising at least two of the repeating units mentioned above, Ph represents a phenylene group, -C(O)- represents a carbonyl group, and each phenylene may independently be of the ortho (1-2), meta (1-3) or para- (1-4) type, preferentially of the meta or para type.

[0038] In certain embodiments, the PAEK can be a PEKK consisting essentially of, or consisting of, terephthalic acid repeat units and isophthalic acid repeat units, the terephthalic acid repeat units having the formula ("T units"): [ka]

[0039] and the isophthalic acid repeat unit has the formula ("I unit"): [ka] has.

[0040] With respect to a given family of polymers, the term "consisting essentially of repeat units" means that the repeat units represent 95% to 99.9% of the molar proportion in the polymer. Further, the term "consisting of repeat units" means that the repeat units represent at least 99.9% of the molar proportion in the polymer, and ideally 100% of the molar proportion.

[0041] In certain embodiments, the PAEK is: formula: [ka] Repeating units and repeating units of: [ka] The polymer may consist essentially of, or even consist of,

[0042] In certain embodiments, the PAEK is: formula: [ka] and a repeating unit of the formula: [ka] The polymer may consist essentially of, or consist of, repeat units of

[0043] In certain embodiments, the PAEK can be a polymer consisting essentially of, or consisting of, repeat units of formula (III).

[0044] Methods involving melt processing In certain embodiments, the present disclosure is directed to methods for preparing carbon-carbon, carbon-ceramic matrix, or carbon-silica composites.

[0045] In certain embodiments, a method for preparing a carbon-carbon composite, a carbon ceramic matrix composite, or a carbon silica composite comprises the steps of: a. preparing a precursor part from a resin comprising polyaryletherketone (PAEK) and at least one toughening additive; b. pyrolyzing the precursor part to produce a pyrolyzed part; c. injecting a liquid second resin into the pyrolyzed part to produce an infused part; d. pyrolyzing the injected component to produce a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite; e. optionally repeating steps (c) through (d) one or more times. Includes.

[0046] In certain embodiments, the present disclosure is directed to a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite made by the above method.

[0047] In certain embodiments, the method can include fabricating a precursor part by melt processing. In certain embodiments, the melt processing can be one or more of injection molding, extrusion, rotational molding, compression molding, pultrusion, filament winding, and fused filament manufacturing printing. In certain embodiments, the melt processing can optionally be followed by melt forming, such as thermoforming or rod bending.

[0048] In certain embodiments, the PAEK can be one or more of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketone-poly(etherdiphenyletherketone) (PEEK-PEDEK), polyetherketone (PEK), and polyetherketoneetherketoneketone (PEKEKK). In certain embodiments, the PAEK can be PEKK.

[0049] In one embodiment, the poly(aryl ether ketone) comprises, consists essentially of, or consists of polyether ketone ketone (PEKK). Polyether ketone ketones suitable for use in the present invention are represented by the following formulas I and II: -AC(=O)-BC(=O)- I -AC(=O)-DC(=O)- II (wherein A is a p,p'-Ph-O-Ph- group, Ph is a phenylene radical, B is p-phenylene, and D is m-phenylene). The polyetherketoneketone may comprise, or consist essentially of, repeat units represented by the following formula I:formula II (T:I) isomer ratios in the polyetherketoneketone may range from 100:0 to 0:100. The isomer ratios may be readily varied, for example, by varying the relative amounts of the different monomers used to make the polyetherketoneketone, as may be desired to achieve a particular set of properties.

[0050] Generally speaking, polyetherketoneketones with a relatively high ratio of Formula I:Formula II will be more crystalline than polyetherketoneketones with a lower ratio of Formula I:Formula II. Thus, the T:I ratio can be adjusted to provide an amorphous (non-crystalline) polyetherketoneketone or a more crystalline polyetherketoneketone, if desired. In one embodiment, a polyetherketoneketone having a T:I isomer ratio of about 50:50 to about 90:10 can be used. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 85:15, about 60:40 to about 80:20, about 65:35 to about 75:25, about 70:30, or any range between the specified ranges.

[0051] In a preferred embodiment, the polyetherketoneketone can have a T:I isomer ratio of 50:50 to 78:22. In practice, these T:I isomer ratios allow for maximization of the char yield for the pyrolyzed parts and minimization of deformation of the precursor parts. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 65:35, especially about 60:40. In some other embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 65:35 to about 75:25, especially about 70:30.

[0052] A suitable polyetherketoneketone is sold under the trade name KEPSTAN® supplied by Arkema.

[0053] The reinforcing additive of the present invention is individual and does not include long and continuous fibers or continuous fabrics, i.e. does not include fibers with a length of more than 20 mm, or in some embodiments, fibers with a length of more than 15 mm, or more than 10 mm, or more than 5 mm. The advantage of using such reinforcing additives to make precursor parts is that they can increase the char content of the pyrolyzed parts, improving their mechanical properties compared to comparable parts made only from polyaryletherketone. At the same time, precursor parts containing polyaryletherketone (PAEK) and at least one reinforcing additive are easier to process than precursor parts made from polyaryletherketone (PAEK) containing long or continuous fibers, especially by high production rate processes such as injection molding or extrusion.

[0054] In certain embodiments, the reinforcing additive may be one or more of a carbon-based additive, chopped fibers, a dispersant, and an inorganic additive, or a mixture thereof.

[0055] In certain embodiments, the additives can be present in an amount of about 0.1% to about 70% by weight of the total resin composition. In certain embodiments, the additives can be present in an amount of about 1% to about 60% by weight of the total resin composition. In certain embodiments, the additives can be present in an amount of about 5% to about 50% by weight of the total resin composition of the precursor part after melt processing.

[0056] In certain embodiments, the toughening additive can be present in an amount of about 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or any range between the specified values, based on the weight of the total composition of the resin of the precursor part after melt processing.

[0057] In a preferred embodiment, the toughening additive may be present in an amount between 20% and 45%, especially between 25% and 40%, based on the weight of the total composition of the resin of the precursor part after melt processing.

[0058] In certain embodiments, the reinforcing additive can be a carbon-based additive. In certain embodiments, the carbon-based additive can be one or more of carbon fiber, carbon nanotube, graphite, graphene, carbon whisker, fullerene, carbon black, carbon flake and buckyball, and mixtures thereof. In certain embodiments, the carbon-based additive can be aligned by shear from melt processing.

[0059] In certain embodiments, the carbon-based additive can have a length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the carbon-based additive can have a length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the carbon-based additive can have a diameter of about 0.1 μm to 10 μm, about 0.5 μm to 9 μm, or about 1 μm to 8 μm. In certain embodiments, the carbon-based additive can have a diameter of about 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, and any range between the specified values. The length of the additive can be measured by optical microscopy before melt compounding. The diameter of the additive can be measured by scanning electron microscopy.

[0060] In certain embodiments, the reinforcing additive can be chopped fibers. In certain embodiments, the chopped fibers include one or more of carbon, glass, silica, boron, natural fibers, and polymer fibers, and mixtures thereof. In certain embodiments, the natural fibers can be one or more of cellulose, bamboo, hemp, and jute. In certain embodiments, the polymer fibers can be one or more of polyamide, polyimide, polyaramid, polyurethane, polyester, and polyurethane, and mixtures thereof.

[0061] In certain embodiments, the chopped fibers are chopped carbon fibers. The one or more carbon fibers can have a fiber length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the chopped carbon fibers can have a fiber length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the chopped carbon fibers can have a diameter of about 0.1 μm to 10 μm, about 0.5 μm to 9 μm, or about 1 μm to 8 μm. In certain embodiments, the chopped carbon fibers can have a diameter of about 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, and any range between the specified values. The length of the additive can be measured by optical microscopy prior to melt compounding, and the diameter of the additive can be measured by scanning electron microscopy.

[0062] A preferred embodiment is directed to a loading level of chopped carbon fiber of 10-45%, or 15-40%, or 20-35%, measured by weight, in a PEKK matrix having a T:I ratio of 55:45 to 85:15.

[0063] More preferred embodiments are directed to a loading level of chopped carbon fiber between 20% to 45%, more particularly 25% to 40%, as measured by weight, in a PEKK matrix having a T:I ratio of 55:45 to 78:22, more particularly a T:I ratio of about 60:40 or about 70:30.

[0064] In certain embodiments, the chopped fibers are chopped glass fibers. The one or more glass fibers can have a fiber length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the chopped glass fibers can have a fiber length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the chopped glass fibers can have a diameter of about 0.1 μm to 10 μm, about 0.5 μm to 9 μm, or about 1 μm to 8 μm. In certain embodiments, the chopped glass fibers can have a diameter of about 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, and any range between the specified values. The length of the additive can be measured by optical microscopy prior to melt compounding, and the diameter of the additive can be measured by scanning electron microscopy.

[0065] A preferred embodiment is directed to a loading level of chopped glass fibers of 10-45%, or 15-40%, or 20-35%, measured by weight, in a PEKK matrix having a T:I ratio of 55:45 to 85:15.

[0066] More preferred embodiments are directed to loading levels of chopped glass fibers between 20% to 45%, more particularly 25% to 40%, as measured by weight, in a PEKK matrix having a T:I ratio of 55:45 to 78:22, more particularly a T:I ratio of about 60:40 or about 70:30.

[0067] In certain embodiments, the strengthening additive can be an inorganic additive. In certain embodiments, the inorganic additive can be one or more of Group IV, V, or VI carbides, silicids, borides, and nitrides. In certain embodiments, the inorganic additive can be in powder form. In certain embodiments, the powder can have an average particle size of about 0.01 μm to 500 μm, about 0.1 μm to 250 μm, about 1 μm to 100 μm, or about 2 μm to 50 μm. In certain embodiments, the powder can have an average particle size of 0.01 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 75 μm, 100 μm, 250 μm, 500 μm, or any range between the specified values.

[0068] In certain embodiments, the toughening additive can include a dispersant. By dispersant, we mean any moiety that improves additive / particle separation and / or prevents agglomeration or settling. In certain embodiments, the dispersant can be an organosilicate, an organozirconate, an organoaluminate, or an organotitanate. In certain embodiments, the dispersant can have an average particle size of about 1 nm to 500 nm, about 2 nm to 250 nm, or about 3 nm to 100 nm. In certain embodiments, the dispersant can have an average particle size of about 1 nm, 2 nm, 3 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 75 nm, 100 nm, 250 nm, 500 nm, or any range between the specified values. The particle size can be determined by scanning electron microscopy of the dispersion prior to melt compounding.

[0069] According to the present invention, during pyrolysis, the temperature in the chamber is increased at a rate of about 1° C. / hour to about 20° C. / hour. Typically, the temperature in the chamber is increased to a peak temperature of about 1000° C. However, in some cases, the temperature in the chamber may be increased to a lower temperature, such as about 850° C. or about 900° C. or about 950° C.

[0070] In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 3° C. / hr to about 17° C. / hr. In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 5° C. / hr to about 15° C. / hr. In certain embodiments, the pyrolysis conditions during pyrolysis step b. are the same as the pyrolysis conditions during pyrolysis step d. In certain embodiments, the pyrolysis conditions during pyrolysis step b. are different from the pyrolysis conditions during pyrolysis step d.

[0071] In certain embodiments, during pyrolysis, the temperature within the chamber may be increased at a rate of about 1° C. / hr, 2° C. / hr, 3° C. / hr, 4° C. / hr, 5° C. / hr, 6° C. / hr, 7° C. / hr, 8° C. / hr, 9° C. / hr, 10° C. / hr, 11° C. / hr, 12° C. / hr, 13° C. / hr, 14° C. / hr, 15° C. / hr, 16° C. / hr, 17° C. / hr, 18° C. / hr, 19° C. / hr, 20° C. / hr, or any range between the specified values.

[0072] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature below 450° C. or below 400° C.

[0073] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature above 600° C. or above 650° C. or higher.

[0074] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of less than 10° C. / hour between 400° C. and 650° C. or between 450° C. and 600° C. In particular, the temperature in the chamber may be increased at a rate of about 1° C. / hour, 2° C. / hour, 3° C. / hour, 4° C. / hour, 5° C. / hour, 6° C. / hour, 7° C. / hour, 8° C. / hour, 9° C. / hour, 10° C. / hour between 400° C. and 650° C. or between 450° C. and 600° C.

[0075] In a preferred embodiment, during pyrolysis of the precursor part, the temperature in the chamber is increased one or more times at a rate of 10°C / hour or more at temperatures below 400°C, at a rate of less than 10°C / hour between 450°C and 600°C, and at a rate of 10°C / hour or more at temperatures above 650°C.

[0076] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10°C / hr to 15°C / hr at temperatures below 400°C, at a rate of 2°C / hr to 5°C / hr at temperatures between 450°C and 600°C, and at a rate of 10°C / hr to 15°C / hr at temperatures above 650°C.

[0077] In certain embodiments, pyrolysis can optionally include a temperature hold during pyrolysis at a temperature between 120°C and 1000°C, or between 200°C and 1000°C, or between 400°C and 1000°C. In certain embodiments, pyrolysis can be performed under nitrogen, argon, or forming gas (a mixture of hydrogen and nitrogen). In certain embodiments, pyrolysis is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold (i.e., maintained) during pyrolysis can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0078] In certain embodiments, pyrolysis of the precursor part can include one or more temperature holds between 400° C. and 650° C. or between 450° C. and 600° C. (inclusive) during pyrolysis. In certain embodiments, pyrolysis of the precursor part can be performed under nitrogen, argon, or forming gas (a mixture of hydrogen and nitrogen). In certain embodiments, pyrolysis of the precursor part is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold (i.e., maintained) during pyrolysis of the precursor part can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0079] In certain embodiments, the liquid second resin comprises, consists essentially of, or consists of one or more of pitch, benzoxazine, furfural, polyester, vinyl ester, acrylic, and phenolic resins, In certain embodiments, the liquid second resin comprises, consists essentially of, or consists of pitch, phenolic resin, or combinations thereof.

[0080] In certain embodiments, the method includes repeating the injection step c. and the pyrolysis step d. at least once. In certain embodiments, the method includes repeating the injection step c. and the pyrolysis step d. at least 2, 3, 4, 5 or more times. In certain embodiments, the char yield after the first pyrolysis cycle, or after 2, 3, 4, 5 or more cycles, can be greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, or greater than 95% or higher.

[0081] In certain embodiments, the method includes repeating the impregnation step c. and the pyrolysis step d. until the carbon-carbon composite, carbon-ceramic matrix composite, or carbon-silica composite is at least about 75% solid, 80% solid, 85% solid, 90% solid, 95% solid, or 99% solid, as measured according to Example 1.

[0082] In certain embodiments, the method comprises repeating steps c. through d. one or more times.

[0083] Methods involving aligned additives In certain embodiments, the present disclosure is directed to a method for preparing a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite.

[0084] In certain embodiments, a method for preparing a carbon-carbon composite, a carbon ceramic matrix composite, or a carbon silica composite comprises the steps of: a1) processing a resin comprising aligned toughening additive and polyaryletherketone (PAEK) to produce aligned toughening additive PAEK, aligned 1-2 dimensional flake material or aligned 1-2 dimensional platelet material to produce a fabric, prepreg or tape comprising aligned toughening additive and impregnated PAEK; a2) processing the PAEK tape, prepreg or fabric to create a precursor object by hand layup, automated tape placement, 3D printing, filament winding or needle punching, or other methods of Z-axis consolidation followed by compression molding, vacuum bag consolidation, autoclave consolidation, in situ consolidation; c. pyrolyzing the object to produce a pyrolyzed object; d. infusing a liquid second resin into the pyrolyzed body to create an infused body; e. pyrolyzing the infused mass to produce a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite; f. Optionally, repeating steps c. through d. one or more times. Includes.

[0085] In certain embodiments, the present disclosure is directed to a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite made by the above method.

[0086] In certain embodiments, the method includes processing a resin including an aligned toughening additive and a polyaryletherketone (PAEK) to produce an aligned toughening additive PAEK. In certain embodiments, the method includes processing a resin including an aligned toughening additive and a polyaryletherketone (PAEK) to produce an aligned 1-2 dimensional flake material. In certain embodiments, the method includes processing a resin including an aligned toughening additive and a polyaryletherketone (PAEK) to produce an aligned 1-2 dimensional platelet material. In certain embodiments, the aligned 1-2 dimensional flake material or the aligned 1-2 dimensional platelet material can be graphite, graphene, or whiskers.

[0087] In certain embodiments, the 1-2D flake material or 1-2D platelet material can have a diameter of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the 1-2D flake material or 1-2D platelet material can have a diameter of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the 1-2D flake material or 1-2D platelet material can have a thickness of about 0.001 mm to 0.1 mm, about 0.005 mm to 0.09 mm, or about 0.01 mm to 0.08 mm. In certain embodiments, the 1-2D flake material or 1-2D platelet material can have a thickness of about 0.001 mm, 0.005 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, and any range between the specified values. Measurements can be obtained from optical or scanning electron microscope imaging prior to melt compounding.

[0088] In certain embodiments, the process can produce a fabric comprising the aligned toughening additive and the impregnated PAEK. In certain embodiments, the process can produce a prepreg comprising the aligned toughening additive and the impregnated PAEK. In certain embodiments, the process can produce a tape comprising the aligned toughening additive and the impregnated PAEK.

[0089] In certain embodiments, the aligned reinforcing additive can be produced by stretching a unidirectional tape until the fibers break and subjecting the fibers to a fluid flow to align the fibers or subjecting the fibers to an electromagnetic field to align the fibers. In certain embodiments, the aligned reinforcing additive can be produced by stretching a unidirectional tape until the fibers break (either before or after impregnation with the PAEK resin). In a preferred embodiment, the fibers are aligned by a fluid flow on a porous belt to produce a mat of aligned fibers as described in US 10,669,659.

[0090] In certain embodiments, the aligned reinforcing additives can be one or more of carbon, glass, silica, boron, natural fibers, polymeric fibers, carbon nanotubes, graphite, graphene, and carbon or ceramic whiskers. In certain embodiments, the natural fibers can be one or more of cellulose, bamboo, hemp, and jute. In certain embodiments, the polymeric fibers can be one or more of polyamide, polyimide, polyaramid, polyurethane, polyester, and polyurethane.

[0091] In certain embodiments, the aligned reinforcing additives can have a length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the aligned reinforcing additives can have a fiber length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values.

[0092] In certain embodiments, the PAEK can be one or more of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketone-poly(etherdiphenyletherketone) (PEEK-PEDEK), polyetherketone (PEK), polyetherketone (PEK), and polyetherketoneetherketoneketone (PEKEKK). In certain embodiments, the PAEK can be PEKK. In some embodiments, PEKK is preferred. In other embodiments, PEEK is preferred.

[0093] In one embodiment, the poly(aryl ether ketone) comprises, consists essentially of, or consists of polyether ketone ketone (PEKK). Polyether ketone ketones suitable for use in the present invention are represented by the following formulas I and II: -AC(=O)-BC(=O)- I -AC(=O)-DC(=O)- II (wherein A is a p,p'-Ph-O-Ph- group, Ph is a phenylene radical, B is p-phenylene, and D is m-phenylene). The polyetherketoneketone may comprise, or consist essentially of, repeat units represented by the following formula I:formula II (T:I) isomer ratios in the polyetherketoneketone may range from 100:0 to 0:100. The isomer ratios may be readily varied, for example, by varying the relative amounts of the different monomers used to make the polyetherketoneketone, as may be desired to achieve a particular set of properties.

[0094] Generally speaking, polyetherketoneketones with a relatively high ratio of Formula I:Formula II will be more crystalline than polyetherketoneketones with a lower ratio of Formula I:Formula II. Thus, the T:I ratio can be adjusted to provide an amorphous (non-crystalline) polyetherketoneketone or a more crystalline polyetherketoneketone, if desired. In one embodiment, a polyetherketoneketone having a T:I isomer ratio of about 50:50 to about 90:10 can be used. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 85:15, about 60:40 to about 80:20, about 65:35 to about 75:25, about 70:30, or any range between the specified ranges.

[0095] In preferred embodiments, the polyetherketoneketone can have a T:I isomer ratio of 50:50 to 78:22. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 65:35, more specifically about 60:40. In some other embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 65:35 to about 75:25, more specifically about 70:30.

[0096] In certain embodiments, in situ consolidation can include rolling to apply pressure and / or heat.

[0097] In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 1° C. / hr to about 20° C. / hr to a peak temperature of about 1000° C. In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 3° C. / hr to about 17° C. / hr. In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 5° C. / hr to about 15° C. / hr. In certain embodiments, the pyrolysis conditions during pyrolysis step c. are the same as the pyrolysis conditions during pyrolysis step e. In certain embodiments, the pyrolysis conditions during pyrolysis step c. are different from the pyrolysis conditions during pyrolysis step e.

[0098] In certain embodiments, during pyrolysis, the temperature within the chamber may be increased at a rate of about 1° C. / hr, 2° C. / hr, 3° C. / hr, 4° C. / hr, 5° C. / hr, 6° C. / hr, 7° C. / hr, 8° C. / hr, 9° C. / hr, 10° C. / hr, 11° C. / hr, 12° C. / hr, 13° C. / hr, 14° C. / hr, 15° C. / hr, 16° C. / hr, 17° C. / hr, 18° C. / hr, 19° C. / hr, 20° C. / hr, or any range between the specified values.

[0099] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature below 450° C. or below 400° C.

[0100] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature above 600° C. or above 650° C. or higher.

[0101] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of less than 10° C. / hour between 400° C. and 650° C. or between 450° C. and 600° C. In particular, the temperature in the chamber may be increased at a rate of about 1° C. / hour, 2° C. / hour, 3° C. / hour, 4° C. / hour, 5° C. / hour, 6° C. / hour, 7° C. / hour, 8° C. / hour, 9° C. / hour, 10° C. / hour between 400° C. and 650° C. or between 450° C. and 600° C.

[0102] In a preferred embodiment, during pyrolysis of the precursor part, the temperature in the chamber is increased one or more times at a rate of 10°C / hour or more at temperatures below 400°C, at a rate of less than 10°C / hour between 450°C and 600°C, and at a rate of 10°C / hour or more at temperatures above 650°C.

[0103] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10°C / hr to 15°C / hr at temperatures below 400°C, at a rate of 2°C / hr to 5°C / hr at temperatures between 450°C and 600°C, and at a rate of 10°C / hr to 15°C / hr at temperatures above 650°C.

[0104] In certain embodiments, pyrolysis can optionally include a temperature hold during pyrolysis. In certain embodiments, pyrolysis can be performed under nitrogen, argon, or forming gas. In certain embodiments, pyrolysis is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0105] In certain embodiments, pyrolysis of the precursor part can include one or more temperature holds between 400° C. and 650° C. or between 450° C. and 600° C. (inclusive) during pyrolysis. In certain embodiments, pyrolysis of the precursor part can be performed under nitrogen, argon, or forming gas (a mixture of hydrogen and nitrogen). In certain embodiments, pyrolysis of the precursor part is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold (i.e., maintained) during pyrolysis of the precursor part can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0106] In certain embodiments, the precursor bodies may be melt-formed after processing step a. but before pyrolysis step c.

[0107] In certain embodiments, the liquid second resin can be one or more of pitch, benzoxazine, furfural, polyester, vinyl ester, acrylic, and phenolic resins, with pitch, phenolic resins, or combinations thereof being preferred in certain embodiments.

[0108] In certain embodiments, the method includes repeating the injection step d. and the pyrolysis step e. at least once. In certain embodiments, the method includes repeating the injection step d. and the pyrolysis step e. at least 2, 3, 4, or 5 times. In certain embodiments, the char yield after the first pyrolysis cycle, or after 2, 3, 4, 5, or more cycles, can be greater than 65%, 70%, 75%, 80%, 85%, 90%, or 95% or higher.

[0109] In certain embodiments, the method includes repeating the infusion step d. and the pyrolysis step e. until the carbon-carbon composite, carbon-ceramic matrix composite, or carbon-silica composite is at least about 75% solid, 80% solid, 85% solid, 90% solid, 95% solid, or 99% solid.

[0110] In certain embodiments, steps c. to d. are repeated one or more times.

[0111] Processes including impregnation or co-weaving steps In certain embodiments, the present disclosure is directed to a method of making a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite.

[0112] In one particular embodiment, a method for making a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite includes the following: a1) impregnating a continuous fiber tape or fabric with a resin comprising polyaryletherketone (PAEK) and at least one reinforcing additive to produce a filled PAEK tape or fabric, or co-weaving the continuous fiber or fabric with a PAEK fiber comprising PAEK and at least one reinforcing additive to produce a filled PAEK tape or fabric; a2) processing the filled PAEK tape or fabric or co-woven PAEK / fiber material to create a precursor part by hand layup, automated tape placement, 3D printing, filament winding or needle punching or other methods of Z-axis consolidation followed by compression molding, vacuum bag consolidation, autoclave consolidation or in situ consolidation; c. pyrolyzing the precursor part to produce a pyrolyzed part; d. injecting a liquid second resin into the pyrolyzed part to produce an infused part; e. pyrolyzing the injected component to produce a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite; Includes.

[0113] In certain embodiments, the present disclosure is directed to a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite made by the above method.

[0114] In certain embodiments, the method includes impregnating a continuous fiber tape or fabric with a resin comprising polyaryletherketone (PAEK) and at least one additive to create a filled PAEK tape. In certain embodiments, the method includes co-weaving a continuous fiber or fabric with a PAEK fiber comprising PAEK and at least one additive to create a filled PAEK tape or fabric.

[0115] In one particular embodiment, the continuous fibers or fabric may be carbon fibers.

[0116] In certain embodiments, the PAEK can be one or more of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketone-poly(etherdiphenyletherketone) (PEEK-PEDEK), polyetherketone (PEK), and polyetherketoneetherketoneketone (PEKEKK). In certain embodiments, the PAEK can be PEKK.

[0117] In one embodiment, the poly(aryl ether ketone) comprises, consists essentially of, or consists of polyether ketone ketone (PEKK). Polyether ketone ketones suitable for use in the present invention are represented by the following formulas I and II: -AC(=O)-BC(=O)- I -AC(=O)-DC(=O)- II (wherein A is a p,p'-Ph-O-Ph- group, Ph is a phenylene radical, B is p-phenylene, and D is m-phenylene). The polyetherketoneketone may comprise, or consist essentially of, repeat units represented by the following formula I:formula II (T:I) isomer ratios in the polyetherketoneketone may range from 100:0 to 0:100. The isomer ratios may be readily varied, for example, by varying the relative amounts of the different monomers used to make the polyetherketoneketone, as may be desired to achieve a particular set of properties.

[0118] Generally speaking, polyetherketoneketones with a relatively high ratio of Formula I:Formula II will be more crystalline than polyetherketoneketones with a lower ratio of Formula I:Formula II. Thus, the T:I ratio can be adjusted to provide an amorphous (non-crystalline) polyetherketoneketone or a more crystalline polyetherketoneketone, if desired. In one embodiment, a polyetherketoneketone having a T:I isomer ratio of about 50:50 to about 90:10 can be used. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 85:15, about 60:40 to about 80:20, about 65:35 to about 75:25, about 70:30, or any range between the specified ranges.

[0119] In a preferred embodiment, the polyetherketoneketone can have a T:I isomer ratio of 50:50 to 78:22. In practice, these T:I isomer ratios allow for maximization of the char yield for the pyrolyzed parts and minimization of deformation of the precursor parts. In some embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 55:45 to about 65:35, especially about 60:40. In some other embodiments, the polyetherketoneketone can have a T:I isomer ratio of about 65:35 to about 75:25, especially about 70:30.

[0120] In certain embodiments, the reinforcing additive may be one or more of a carbon-based additive, a chopped fiber, a dispersant, and an inorganic additive.

[0121] In certain embodiments, the additive may be present in an amount of about 0.01% to about 30% by weight of the total resin composition. In certain embodiments, the additive may be present in an amount of about 0.1% to about 25% by weight of the total resin composition. In certain embodiments, the additive may be present in an amount of about 1% to about 20% by weight of the total resin composition.

[0122] In certain embodiments, the additives can be present in an amount of about 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30% by weight of the total resin composition, or any range between the specified values.

[0123] In certain embodiments, the additive can be a carbon-based additive. In certain embodiments, the carbon-based additive can be one or more of carbon fiber, carbon nanotube, graphite, graphene, carbon whisker, fullerene, carbon black, carbon flake, and buckyball. In certain embodiments, the carbon-based additive can be aligned by shear from melt processing.

[0124] In certain embodiments, the carbon-based additive can have a length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the carbon-based additive can have a length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the carbon-based additive can have a diameter of about 0.1 μm to 10 μm, about 0.5 μm to 9 μm, or about 1 μm to 8 μm. In certain embodiments, the carbon-based additive can have a diameter of about 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, and any range between the specified values.

[0125] In certain embodiments, the additive can be chopped fibers. In certain embodiments, the chopped fibers include one or more of carbon, glass, silica, boron, natural fibers, and polymer fibers. In certain embodiments, the natural fibers can be one or more of cellulose, bamboo, hemp, and jute. In certain embodiments, the polymer fibers can be one or more of polyamide, polyimide, polyaramid, polyurethane, polyester, and polyurethane.

[0126] In certain embodiments, the chopped fibers are chopped carbon fibers. The one or more carbon fibers can have a fiber length of about 0.1 mm to 10 mm, about 0.5 mm to 9 mm, or about 1 mm to 8 mm. In certain embodiments, the chopped carbon fibers can have a fiber length of about 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, and any range between the specified values. In certain embodiments, the chopped carbon fibers can have a diameter of about 0.1 μm to 10 μm, about 0.5 μm to 9 μm, or about 1 μm to 8 μm. In certain embodiments, the chopped carbon fibers can have a diameter of about 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, and any range between the specified values.

[0127] In certain embodiments, the additive can be an inorganic additive. In certain embodiments, the inorganic additive can be one or more of carbides, silicides, borides, and nitrides of Group IV, V, or VI. Carbides and silicides are preferred, with silicon carbide being most preferred. In certain embodiments, the inorganic additive can be in powder form. In certain embodiments, the powder can have an average particle size of about 0.01 μm to 500 μm, about 0.1 μm to 250 μm, about 1 μm to 100 μm, or about 2 μm to 50 μm. In certain embodiments, the average particle size of the powder can be 0.01 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 75 μm, 100 μm, 250 μm, 500 μm, or any range between the specified values.

[0128] In certain embodiments, the additive can include a dispersant. In certain embodiments, the dispersant can be an organosilicate, an organozirconate, an organoaluminate, or an organotitanate, with organosilicates and organotitanates being preferred, and organosilicates being most preferred. In certain embodiments, the dispersant can have an average pore size of about 1 nm to 500 nm, about 2 nm to 250 nm, or about 3 nm to 100 nm. In certain embodiments, the dispersant can have an average pore size of about 1 nm, 2 nm, 3 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 75 nm, 100 nm, 250 nm, 500 nm, or any range between the specified values.

[0129] In certain embodiments, in situ consolidation can include rolling to apply pressure and / or heat.

[0130] In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 1° C. / hr to about 20° C. / hr to a peak temperature of about 1000° C. In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 3° C. / hr to about 17° C. / hr. In certain embodiments, during pyrolysis, the temperature in the chamber may be increased at a rate of about 5° C. / hr to about 15° C. / hr. In certain embodiments, the pyrolysis conditions during pyrolysis step c. are the same as the pyrolysis conditions during pyrolysis step e. In certain embodiments, the pyrolysis conditions during pyrolysis step c. are different from the pyrolysis conditions during pyrolysis step e.

[0131] In certain embodiments, during pyrolysis, the temperature within the chamber may be increased at a rate of about 1° C. / hr, 2° C. / hr, 3° C. / hr, 4° C. / hr, 5° C. / hr, 6° C. / hr, 7° C. / hr, 8° C. / hr, 9° C. / hr, 10° C. / hr, 11° C. / hr, 12° C. / hr, 13° C. / hr, 14° C. / hr, 15° C. / hr, 16° C. / hr, 17° C. / hr, 18° C. / hr, 19° C. / hr, 20° C. / hr, or any range between the specified values.

[0132] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature below 450° C. or below 400° C.

[0133] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10° C. / hour or greater to a temperature above 600° C. or above 650° C. or higher.

[0134] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased at a rate of less than 10° C. / hour one or more times between 400° C. and 650° C. or between 450° C. and 600° C. In particular, the temperature in the chamber may be increased at a rate of about 1° C. / hour, 2° C. / hour, 3° C. / hour, 4° C. / hour, 5° C. / hour, 6° C. / hour, 7° C. / hour, 8° C. / hour, 9° C. / hour, 10° C. / hour between 400° C. and 650° C. or between 450° C. and 600° C.

[0135] In a preferred embodiment, during pyrolysis of the precursor part, the temperature in the chamber is increased one or more times at a rate of 10°C / hour or more at temperatures below 400°C, at a rate of less than 10°C / hour between 450°C and 600°C, and at a rate of 10°C / hour or more at temperatures above 650°C.

[0136] In certain embodiments, during pyrolysis of the precursor parts, the temperature in the chamber is increased one or more times at a rate of 10°C / hr to 15°C / hr at temperatures below 400°C, at a rate of 2°C / hr to 5°C / hr at temperatures between 450°C and 600°C, and at a rate of 10°C / hr to 15°C / hr at temperatures above 650°C.

[0137] In certain embodiments, pyrolysis can optionally include a temperature hold during pyrolysis. In certain embodiments, pyrolysis can be performed under nitrogen, argon, or forming gas. In certain embodiments, pyrolysis is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0138] In certain embodiments, pyrolysis of the precursor part can include one or more temperature holds between 450° C. and 600° C. (inclusive) during pyrolysis. In certain embodiments, pyrolysis of the precursor part can be performed under nitrogen, argon, or forming gas (a mixture of hydrogen and nitrogen). In certain embodiments, pyrolysis of the precursor part is performed on a graphite bed. In certain embodiments, the temperature hold during pyrolysis can be about 1 hour to 72 hours, about 2 hours to 48 hours, or about 3 hours to 24 hours. In certain embodiments, the temperature hold (i.e., maintained) during pyrolysis of the precursor part can be about 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 16 hours, 20 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 ​​hours, 54 hours, 60 hours, 66 hours, 72 hours, or any range between the specified values.

[0139] In certain embodiments, the precursor bodies may be melt-formed after processing step b. but before pyrolysis step c.

[0140] In certain embodiments, the liquid second resin can be one or more of pitch, benzoxazine, furfural, polyester, vinyl ester, acrylic, and phenolic resins.

[0141] In certain embodiments, the method includes repeating the injection step d. and the pyrolysis step e. at least once. In certain embodiments, the method includes repeating the injection step d. and the pyrolysis step e. at least 2, 3, 4, or 5 or more times. In certain embodiments, the char yield after the first pyrolysis cycle, or after 2, 3, 4, 5 or more cycles, can be greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, or greater than 95% or higher.

[0142] In certain embodiments, the method includes repeating the infusion step d. and the pyrolysis step e. until the carbon-carbon composite, carbon-ceramic matrix composite, or carbon-silica composite is at least about 75% solid, 80% solid, 85% solid, 90% solid, 95% solid, or 99% solid. EXAMPLES

[0143] The methods and products described herein will now be further described with reference to the following examples. These examples are presented for illustrative purposes only, and the embodiments described herein should in no way be construed as being limited to these examples. Rather, the embodiments should be construed to encompass any and all variations that become evident as a result of the teachings presented herein.

[0144] (Example nb 1) Pyrolysis of 0-40% carbon filled PAEK resins. Several variations of the proposed invention were evaluated for char yield. Injection molded tensile bars containing neat resin (varying T / I contents from 60 / 40 to 80 / 20) and short chain chopped carbon fiber (0-40%) were analyzed (Table 1). Tensile bars made of PEKK alone represent comparative examples, while the examples containing 40% chopped carbon fiber are of the invention.

[0145] [Table 1]

[0146] All samples were subjected to the following pyrolysis cycle under an inert atmosphere (10-15 LPM nitrogen flow throughout) (Table 2).

[0147] [Table 2]

[0148] The char yield was calculated from the mass of each sample before and after pyrolysis ("Equation 1"):

[0149]

number

[0150] (In the formula, w b and w a are the masses of the sample before and after pyrolysis, respectively). The results are summarized below (Table 3). It can be seen that inventive Example E, shown in FIG. 1, containing carbon fiber filler, had a significantly higher char yield than Comparative Examples A-D.

[0151] [Table 3]

[0152] (Example nb 2) Effect of T / l ratio of PEKK samples PEKK samples ("Table 4") with various T / I ratios (60 / 40; 80 / 20) and 30% chopped fibers (either glass or carbon) were manufactured by injection molding, pyrolyzed in quartz crucibles in a muffle furnace in an inert environment, and subjected to the following pyrolysis cycle ("Table 5"). Their initial dimensions were all approximately 5.1 cm x 1.3 cm x 0.3 cm.

[0153] [Table 4]

[0154] [Table 5]

[0155] Samples F and G were weighed, their thickness (t) was measured before and after pyrolysis, the char yield was calculated, and the dimensional change (Table 6) was determined. The parameter Δt refers to the difference between the thickness after pyrolysis and the thickness at 25° C. before pyrolysis divided by the thickness at 25° C. before pyrolysis (expressed as a percentage).

[0156] [Table 6]

[0157] Example F (60:40 T:I ratio) showed a slight improvement in char yield when compared to Example G (80:20 T:I ratio). More significantly, Example F showed an almost 3x reduction in sample expansion, as measured by dimensional change in thickness, when compared to Example G.

[0158] (Example nb 3) Effect of temperature rise profile during pyrolysis Samples of polyetheretherketone (PEKK) with various T / I ratios (60 / 40, 70 / 30, 80 / 20) and polyetheretherketone (PEEK; homopolymer consisting of repeating units of formula (III)) with various short-chain chopped carbon fiber contents (0-40 wt%) were produced by injection molding and pyrolyzed in quartz crucibles in a muffle furnace in an inert environment at a slow ramp rate (subject to the pyrolysis cycle in Table 5) and with an extended hold up to 1000 °C. As a comparison, a similarly prepared comparative sample was pyrolyzed using a faster ramp rate (set at 20°C / min) with a 3 hour hold at 1000°C in an inert environment. Although the furnace was set at a faster ramp rate, the furnace did not perform well at such a fast rate and was estimated to perform closer to 1-5°C / min. The samples were weighed and their thicknesses were measured before and after pyrolysis to calculate the char yield and determine the dimensional change.

[0159] [Table 7]

[0160] It was observed that for all comparable samples, the fast pyrolysis ramps caused significantly higher dimensional changes and comparable or slightly higher char yields than the slow ramps. Furthermore, neat PEEK appears to have a significantly lower char yield than neat PEKK under the same pyrolysis conditions.

Claims

1. 1. A method for making a high temperature composite, which is a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite, comprising: a. fabricating a precursor part from a resin comprising polyaryletherketone (PAEK) and at least one toughening additive; b. pyrolyzing the precursor component in a chamber to form a pyrolyzed component; c. infusing a liquid second resin into the pyrolyzed part to create an infused part; d. pyrolyzing the injected component in a chamber to produce a carbon-carbon composite, a carbon-ceramic matrix composite, or a carbon-silica composite; e. Optionally, repeating steps c. through d. one or more times. Including, A method wherein the temperature in a chamber is increased one or more times during said pyrolysis at a rate of between 1°C / hr and 20°C / hr, and optionally said pyrolysis is maintained at one or more temperatures for a period of time.

2. 10. The method of claim 1, wherein the PAEK comprises one or more of polyetherketoneketone (PEKK), polyetheretherketone (PEEK), polyetheretherketone-poly(etherdiphenyletherketone) (PEEK-PEDEK), polyetherketone (PEK), and polyetherketoneetherketoneketone (PEKEKK).

3. The method of claim 2 , wherein the PAEK comprises a polyetherketoneketone.

4. 4. The method of claim 3, wherein the polyetherketoneketone has a T:I isomer ratio of 50:50 to 78:

22.

5. 10. The method of claim 1, wherein the temperature in the chamber is increased to a peak temperature of 1000°C or greater during pyrolysis.

6. 10. The method of claim 1, wherein during pyrolysis of the precursor part, the temperature in the chamber is increased one or more times between 450°C and 600°C at a rate of less than 10°C / hour, and optionally maintained for a period of time at one or more temperatures between 450°C and 600°C, inclusive.

7. 10. The method of claim 1, wherein during pyrolysis of the precursor part, the temperature in the chamber is increased one or more times at a rate of 10°C / hour or greater to temperatures below 400°C and / or above 650°C.

8. 8. The method of any one of claims 1 to 7, wherein the liquid second resin comprises one or more of pitch, benzoxazine, furfural, polyester, vinyl ester, acrylic, and phenolic resins.

9. 8. The method of claim 1, wherein the reinforcing additive comprises chopped carbon fibers.

10. 8. A carbon-carbon composite, a carbon-ceramic matrix composite or a carbon-silica composite made by the method of any one of claims 1 to 7.