Compositions eliminating onset of translational mobility in cured polymers

Abstract

The disclosure relates to cured polymer compositions exhibiting improved thermomechanical properties over large temperature ranges. More specifically, the disclosure relates to systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperature ranges.

Description

COMPOSITIONS ELIMINATING ONSET OF TRANSLATIONAL MOBILITY IN CURED POLYMERSBACKGROUND

[0001] The disclosure is directed to cured polymer compositions exhibiting improved thermomechanical properties over large temperature ranges. More specifically, the disclosure is directed to systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperature ranges.

[0002] Additive manufacturing, prioritizing materials with an onset temperature of translational mobility of critical chain length that is higher (e.g., PEI, Tg=~220 °C), expands its applicability across industries that demand high thermal stability and mechanical performance. In aerospace, where lightweight, high-strength materials are crucial, 3D printing with higher Tg polymers becomes essential for crafting components like advanced engine parts, structural elements, and thermally resistant housing for sensitive equipment. Likewise, the automotive industry benefits from these materials for producing components exposed to extreme temperatures, such as under-the- hood applications and exhaust systems, ensuring improved durability and performance. Furthermore, in electronics, particularly for sophisticated electronic devices and circuits prone to high temperatures during operation, materials with a higher Tg become integral for maintaining structural integrity and reliability. In addition, applications in the oil and gas sector, where downhole tools and equipment endure harsh thermal and chemical conditions, necessitate materials with an elevated onset temperature of translational mobility for increased durability and lifespan.

[0003] One significant 3D printing application requiring materials with a high onset temperature of translational critical chain length mobility (glass transition temperature (Tg) is the fabrication of Integrated Circuit (IC) packages and printed circuit boards (PCBs). IC packages serve as protective enclosures for semiconductor devices, ensuring their functionality and reliability. The high Tg of the final product can be crucial in this context due to the demanding operating conditions and thermal stresses that IC packages and PCBs may experience during their lifecycle.

[0004] In the context of applications requiring materials with an elevated onset temperature of translational critical chain length mobility, Stereolithography (SLA), Digital Light Processing (DLP), and Inkjet Printing offer advantages over Fused Filament Fabrication (FFF) and FusedDeposition Modeling (FDM). SLA and DLP utilize liquid resin photopolymers cured layer by layer with precision, enabling the creation of intricate, high-resolution parts. This precision is particularly beneficial for applications in aerospace, automotive, electronics, and industrial tooling, where complex geometries and fine details are crucial. Inkjet Printing, depositing liquid materials onto a build platform, allows for the utilization of a wide range of materials, including high-temperature- resistant polymers, offering versatility in material selection. While FFF and FDM excel in rapid prototyping and are well-suited for certain applications, SLA, DLP, and Inkjet Printing stand out in scenarios demanding intricate designs, high resolution, and diverse material capabilities.

[0005] Utilizing inherently high glass transition temperature (Tg) materials like polyetheretherketone (PEEK), polyetherimide (PEI), and polyphenylene sulfide (PPS) in additive manufacturing processes such as Stereolithography (SLA), Inkjet Printing, and Digital Light Processing (DLP) poses several challenges. These materials demand elevated processing temperatures or different curing procedures during 3D printing for fundamental reasons.

[0006] The heightened temperatures enable the transformation of these polymers from a solid to a molten state, ensuring optimal flowability, molecular alignment, and layer adhesion, promoting the creation of structurally sound and homogeneous printed objects. Additionally, high temperatures help alleviate internal stresses, prevent material decomposition, and facilitate fusion between layers, ensuring the final 3D-printed parts possess the desired mechanical properties and thermal stability. While necessitating advanced equipment and energy considerations, these elevated processing temperatures are vital for achieving the intended performance characteristics of these high- performance materials.

[0007] These often-necessitated elevated processing temperatures typically surpass the capabilities of certain 3D printing technologies. In SLA, the operating temperatures typically employed are not sufficient to handle the high Tg requirements and the presence of solvents of thermoplastic materials like PEEK or PEI. Similarly, in Inkjet Printing, the operating temperatures are generally lower than what is needed for effective processing of these polymers. Likewise, DLP may face challenges in processing the solvents present in the ink composition (if operating at the typical processing temperatures), and / or achieving the elevated temperatures required for proper curing and post-curing of high Tg materials.

[0008] Thus, there is a need for compositions, systems and methods enabling efficient and precise fabrication of complex articles of component with increased thermomechanical stability.SUMMARY

[0009] Disclosed, in various exemplary implementations, are systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperature ranges.

[0010] In an exemplary implementation, provided herein is a method of substantially eliminating the onset of translational mobility of a polymer chain segment following phase change, over a predetermined temperature range, the method comprising forming a curable liquid composition comprising: admixing into a solution comprising a multifunctional acrylate polymer or its oligomer, a multifunctional crosslinking agent (MCA) and a photoinitiator (PI) at a predetermined volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA; and curing the curable liquid composition, thereby forming a cured polymer network, wherein the fractional concentration of the MCA in cured polymer network is configured to be above the three dimensional (3D) bond percolation threshold of the cured polymer network.

[0011] In another exemplary implementation, provided herein is a curable dielectric ink composition configured, upon curing, to substantially eliminate the onset of translational mobility of a polymer’s chain, or its oligomer segment over a predetermined temperature range comprising: a multifunctional acrylate polymer or its oligomer; a multifunctional crosslinking agent (MCA); and (optionally) a photoinitiator (PI), wherein the volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA is between 1:10 and 11:20.

[0012] These and other features of the methods and compositions for fabricating components and / or articles exhibiting no onset temperature indicative of translational mobility of critical polymer or oligomer chain length, shall become apparent from the following detailed description when read in conjunction with the figures and examples, which are exemplary, not limiting.BRIEF DESCRIPTION OF THE FIGURES

[0013] For a better understanding of the systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperatureranges, with regard to the exemplary implementations thereof, reference is made to the accompanying examples and figures, in which:

[0014] FIG. 1A DMA & TGA Curve of an example polymer system, while FIG. IB is a schematic DMA-curves of polymer blends and their corresponding Homo-polymers;

[0015] FIG. 2A illustrates TMA Tests of different resin compositions, and 2B is a schematic TMA diagram of a thermoset;

[0016] FIG. 3, illustrates the effect of composition on thermal decomposition and out-gassing of the printed specimens; and

[0017] FIG.4 illustrates the effect of composition on Young’s modulus;

[0018] FIGs 5A-5C illustrate the effect of BMl / Methacrylate ratio on measured thermomechanic al ;

[0019] FIG. 6, illustrates the effect of the loading, size and surface-modification of the silica nanoparticlcs on the viscosity of the base resin;

[0020] FIG. 7, illustrates the effect of BMI concentration on thermogravimetric analysis;

[0021] FIG. 8, illustrates the effect of BMI type and concentration on the storage modulus;

[0022] FIG. 9, illustrates the effect of thermal initiator (TI) type and concentration on stiffness of the polymerized resin;

[0023] FIG. 10, illustrates the effect of BMI type and the presence of TI on the storage modulus;

[0024] FIG. 11 , illustrates the effect of BMI at the same concentration on the storage modulus; and

[0025] FIG. 12, illustrates a differential scanning calorimetry analysis of the BMI-containing resin.DETAILED DESCRIPTION

[0026] Provided herein are exemplary implementations of systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperature ranges.

[0027] The combination of (Meth-) Acrylate and bis-melaimide (BMI) resins leads to materials with extraordinary thermal properties. Polymers typically have a defined glass transition temperature(Tg), or softening point, at which the polymeric network gains translational chain mobility and thus the material shows significant decrease in mechanical properties, e.g., tensile strength and Young’s modulus, as well as an increase of the coefficient of thermal expansion (CTE), impact strength & elongation at break.

[0028] Typically, when mixing two or more types of polymers, the resulting resin, depending on the thermodynamic compatibility between (among) the polymers, will exhibit either multiple glass transition temperatures (see e.g., FIG. IB), corresponding to the individual components, or a defined glass transition temperature, somewhere between the Tg’s of the individual polymer and as afunction of their fractional concentration. By combining (Meth-)Acrylates and BMI, the glass transition temperature of the resulting polymer shifts to a temperatures that is higher than of those of the individual components (in other words, the Tgs of the pure acrylate and the pure BMI. This shift can be so significant that the glass transition temperature vanishes completely as the material decomposes before it reaches the shifted theoretical glass transition temperature.

[0029] Whereas typical polymers exhibit temperature stabilities of up to 250°C, the combination of (Meth-) Acrylate and BMI lead in certain exemplary implementations, to materials having a temperature stability to changes in thermomechanical properties of up to 35O°C, thereby opening entirely new high-temperature fields of applications for polymers.

[0030] In products formed of polymers and polymer blends, the glass transition temperature (Tg) is a crucial parameter affecting thermomechanical properties that drive material behavior. Polymers undergo a transition from a rigid, glassy state to a more flexible, rubbery state as the temperature surpasses Tg. As temperature increases, the free volume (Vf, referring to the voids in the amorphous regions of polymers or free spaces between polymer chains, and the mobility of polymer chains is strongly influenced by these free volumes) of the system increases, to the point where the free volume, is larger than that critical chain length (representing the minimum polymer length required for polymer chains to exhibit cooperative motion), thereby facilitating the (glass) transition.

[0031] This kinematic (in other words, time-related) transition significantly impacts key characteristics such as modulus, hardness, and thermal expansion. The storage modulus (E') and loss modulus (E") undergo notable changes in the vicinity of Tg, marking shifts in material stiffness and energy dissipation. Additionally, Tg influences the coefficient of thermal expansion, affecting dimensional stability and response to temperature variations. In polymer blends, the glass transition becomes a complex interplay of multiple Tg values, resulting in a broadened transition range anddiverse mechanical responses. The damping behavior, often associated with viscoelasticity, experiences alterations due to Tg-related transitions, affecting material resilience and fatigue resistance. Furthermore, the glass transition influences creep and stress relaxation, crucial parameters in applications where long-term mechanical performance is critical.

[0032] Furthermore, dielectric properties, such as, for example, dielectric loss (E) are also affected by Tg. In the case of dielecetric loss, as the temperature increases over Tg and the material transitions into a more flexible, rubbery state, the increased molecular mobility allows for greater polarization and alignment of dipoles in response to an electric field. For example, the disclosed formulation produce dielectric material exhibiting dielectric loss of less than 0.005, and a dielectric constant of between about 2.5 and about 3.0 at RT.

[0033] Here too, thermo-mechanical properties, such as, for example one of: coefficient of thermal expansion (a), tensile strength, Young's Modulus (E), Glass Transition Temperature (Tg), and the brittle-ductile transition temperature (Tp), and [Tp / Tg] ratio, each as measured on the cured layer, can be further improved composition by controlling a plurality of parameters, for example, at least one of: the type of monomer used, degree of polymerization, cross-link density, fractional concentration of the monomer, oligomer and / or polymer and their combination in the composition, and the like.

[0034] Accordingly, and in an exemplary implementation, provided herein is a method of substantially eliminating the onset of translational mobility of a polymer chain segment following phase change (in other words, as a result of heating by increasing temperature at a certain rate), over a predetermined temperature range, the method comprising forming a curable liquid composition comprising: admixing into a solution comprising a multifunctional acrylate polymer or its oligomer, a multifunctional crosslinking agent (MCA) and (optionally) a photoinitiator (PI) at a predetermined volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA; and curing the curable liquid composition, thereby forming a cured polymer network, wherein the fractional concentration of the MCA in cured polymer network is configured to be above the three dimensional (3D) bond percolation threshold of the cured polymer network.

[0035] In the context of the disclosure, the term “curing” refers to the process by which the cross-linking or curing agent such as photopolymerization initiators (PI) react with the cross-linkable functional groups to form the cross-linked network characteristic of a cured compositions. The cured compositions as employed herein is, in certain exemplary implementations, refer to a non-deformablesolid exhibiting limited or no solubility in conventional solvents. “When cured”, as used herein with reference to the compositions as a basis for weight fractions of, for example, fillers, means that portion of the thermoset resin composition remaining in solid form after curing, which excludes solvents, volatiles, and volatile reaction components that may be generated during curing. Reaction products are only generated during curing, and not after, since any reaction will have been completed (termination reactions) when curing is done. Curing is carried out in certain implementations, by exposing the various composition to actinic radiation in a predetermined wavelength, such as between about 190 nm and about 470 nm for a predetermined time, for example between about 5 milliseconds (ms) and about 10 minutes, depending on the compositions and the thermo-mechanical parameters sought to be improved and / or modulated.

[0036] Further, the term “percolation” as used herein, is assigned to the theory of connectivity of MCAs (each having at least three (3) functional ends), in randomized lattice structures. Likewise, the term “percolation threshold” is used herein to refer, for example, to a state achieved when a crosslinked phase forms a continuous, at least three dimensional (3D) interconnecting network throughout the bulk resin. In other words, the continuous crosslinked phase is one where the crosslinked polymer phase is substantially uniformly distributed within the whole volume of the bulk phase (referring to uniform physical and / or chemical composition).

[0037] For example, the multifunctional acrylate composition can be a branched resin whereby thermo-mechanical properties can be controlled by the degree of branching, backbone length between branches, cross link density and the like. For example, the multifunctional acrylate composition can further comprise polyester (PES), polyethylene (PE), polyvinyl alcohol (PVOH), poly(vinylacetate) (PVA), Poly(vinylpirrolidone), or a combination comprising a mixture, a monomer, an oligomer, and a copolymer of one or more of the foregoing.

[0038] As such, the multi-functional acrylate used for substantially eliminating the onset of translational mobility of a polymer chain segment following phase change, over a predetermined temperature range (e.g., between -25 °C (or 248 K) and 350 °C), used in the methods disclosed herein, can be at least one of a monomer, oligomer, polymer, and copolymer of: 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol-A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate,polyethylene glycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tris(2- acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate or a multifunctional acrylate composition comprising one or more of the foregoing.

[0039] Other matrix (build materials) can be used and comprise, for example vinylbenzyl compound resin, a polyolefin compound, a maleimide resin, urethane resin, urethane-modified polyester resin, or a combination thereof. For example, the vinylbenzyl compound resin is vinylbenzyl etherified-bicyclopentadiene phenol resin; the polyolefin compound is at least one of styrene- butadiene-divinylbenzene copolymer, hydrogenated styrene-butadiene-divinylbenzene copolymer, styrene-butadiene-maleic anhydride copolymer, polybutadiene-urethane-methyl methacrylate copolymer, urcthanc-mcthyl methacrylate copolymer, styrcnc-butadicnc copolymer, polybutadicnc homopolymer, styrene-isoprene- styrene copolymer, maleinized styrene-butadiene copolymer, methylstyrene copolymer, petroleum resin and cyclic olefin copolymer.

[0040] In an exemplary implementation, the MCA comprises a Bismaleimide (BMI) monomer, oligomer or polymer represented by the formula:where: - x is an aliphatic spacer, an aromatic spacer, or their combination.

[0001] For example, x is an aliphatic chain having the general formula (CH2)n, wherein n is an integer between 1 and 1500.

[0042] For example, the BMI resin used can be at least one of 4,4'-bismaleimidodiphenyl methane (MDAB), phenylmethane maleimide oligomer, N,N'-m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3 '-dimethyl-5, 5 '-diethyl-4, 4 '-diphenylmethane bismaleimide, N,N'- (4- methyl- 1,3 -phenylene) bismaleimide, l,6-bismaleimido-(2,2,4-trimethyl)hexane (MATMD), 2,3-dimethylphenylmaleimide, 2,6-dimethylphenylmaleimide, N-phenylmaleimide, 2,4- bismaleimidotoluene (TDAB), (1,1 -(meth ylenedi-4,1 -phenylene) bismaleimide (MDPB), bis(3- methyl-5-ethyl-4-maleimidophenyl) methane, a 2,2-bis(4-maleimido phenoxyphenyl)propane, (5,6- (diheptylen-phenylene) bismaleimide, bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, m- xylylenebismaleimide (MXBI), and the prepolymer of the abovementioned compound.

[0043] In another exemplary implementation, the volume ratio (V / V) between the BMI and the acrylate polymer, or oligomer is between 1:10 and 11:20.

[0044] Photoinitiators that can be used with the acrylates described herein can be, for example radical photoinitiators. These radical photoinitiators can be, for example Irgacure® 500 from CIBA SPECIALTY CHEMICAL and Darocur® 1173, Irgacure® 819, Irgacure® 184, TPO-L (ethyl(2,4,6, trimethyl benzoil) phenyl phosphinate) benzophenone and acetophenone compounds and the like. For example, the radical photoinitiator can be cationic photo-initiator, such as mixed triarylsulfonium hcxafluoroantimonatc salts. Another example of the free radical photoinitiator used, is at least one of: be 2-ispropylthioxanthone (ITX), 2,4-Diethylthioxanthone (DETX), benzophenone, 4- methylbenzophenone, ethyl-4-dimethylaminobenzoate (EDAB), and 2,2-Dimethoxy-2- phenylacetophenone. In an exemplary implementation, two or more Pi’s are used, for example, ITX and EDAB, or in another example, EDAB, ITX and TPO-L.

[0045] In an exemplary implementation, the fractional volume concentration of the MCA in the cured polymer network (in other words, in its solid state), is between about 16% and about 50% (v / v).

[0046] For example, in an implementation, the BMI is bis (1,2 maleimidoheptane) 5,6- diheptenyl cyclohexene, and the multifunctional acrylate is: Tris (2-hydroxy ethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate, at a BMLto the multifunctional acrylate (in other words, the Tris (2-hydroxy ethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate) ratio of 1:3.

[0047] In another exemplary implementation, the methods disclosed are used to create a curable dielectric ink composition, that will form a dielectric ink to be used in various additive manufacturing printer, for example, inkjet printing, stereolithography (STL), and digital light printing (DLP). Accordingly, provided herein is a curable dielectric ink composition configured, upon curing, to substantially eliminate the onset of translational mobility of a polymer’s chain, or its oligomer segment at a predetermined temperature range comprising: a multifunctional acrylate polymer or itsoligomer; a multifunctional crosslinking agent (MCA); and (optionally) a photoinitiator (PI), wherein the volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA is between 1:10 and 11:20.

[0048] The term “forming” (and its variants "formed", etc.) refers in an exemplary implementation to pumping, injecting, pouring, releasing, displacing, spotting, circulating, or otherwise placing a fluid or material (e.g., the conductive ink) in contact with another material (e.g., the substrate, the resin or another layer) using any suitable manner known in the art.

[0049] The printed Dl / resinous ink can be fabricated from resin-rich ink compositions, for example, suspensions, emulsions, solutions and the like. The term “resin-rich” refers to compositions in which larger proportions of polymer resin components are included than are needed to bind the Dl / resinous ink layer to the underlying substrate, conductive layer, or to a layer of another component having resinous / dielectric, and metallic / conductive constituents with voids therein, or support portion and their combination. For example, a resin-rich component layer may include polymer Dl / resins in amounts that are at least 95% by weight of the total Dl / rcsin ink weight.

[0050] The term "comprising" and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and / or steps. The foregoing also applies to words having similar meanings such as the terms, "including", "having" and their derivatives.

[0051] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “a”, “an” and “the” herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the constituent(s) includes one or more constituent). Reference throughout the specification to “one exemplary implementation”, “another exemplary implementation”, “an exemplary implementation”, and so forth, when present, means that a particular element (e.g., feature, structure, and / or characteristic) described in connection with the exemplary implementation is included in at least one exemplary implementation described herein, and may or may not be present in other exemplaryimplementations. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various exemplary implementations.

[0052] Likewise, the term "about" means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is "about" or "approximate" whether or not expressly stated to be such.EXAMPLESMaterials'.

[0053] BML689 (Designer Molecules Inc.) was mixed with the acrylates Miramer M410 (Di(Trimcthylolpropanc) tctraacrylatc), Miramer M600 (Rahn Chcmic, Dipcntacrythriolhcxaacrylatc), SR368 (Tris (2-hydroxy ethyl) isocyanuratetriacrylate) and SR833S (Arkema Satomer, Tricyclodecanedimethanol Diacrylate) as well as with the methacrylate SR834 (Arkema Satomer, Tricyclodecanedimethanol Dimethacrylate) at mass fractions (w / w) 25:75, 50:50 and 75:25. The raw materials were used as received. To fabricate UV-curable resins 1 wt.% TPO-L (Arkema Satomer) was added to base resin. Furthermore silica nanoparticles (Denka Chemicals) with and without an methacrylate surface modification and different size distribution were dispersed in the base resin with a 3-Stage-Mill (EXAKT) at weight concentrations of 35.5, 48 and 59 wt.%.Methods:Viscosity

[0054] The viscosity of the base resin was measured with a hybrid rheometer DHR20 (WATERS™ I TA Instruments) with a plate / plate-geometry at shear rates between 1 and 1000 1 / s between 30 and 80 °C with three measurement points per order of magnitude.TMA

[0055] The thermal expansion of the material was measured with thermomechanical analyzer TMA 450 (WATERS™ I TA Instruments) with two heat-up and one cool-down cycle with a heating resp. cooling rate of 3 K / min from -10 to 300 °C.TGA

[0056] The thermal decomposition of the material was measured with thermogravimetric analyzer TGA 550 (WATERS™ I TA Instruments) with a heating rate of 10 K / min until 800°C in a platinum crucible. Below 600°C the probe was flushed with dry nitrogen. Above 600°C the probe was flushed with dry oxygen.DMA

[0057] The thermo-mechanical properties were tested with a hybrid rheometer DHR20 (WATERS™ I TA Instruments) in a temperature range from 25°C to 400°C with a heating rate of 3 K / min with a dynamic load of 0.1 % with a frequency of 1 Hz and a preload of 0.5%.DSC

[0058] DSC and Cp measurements were performed with a DSC 204 Fl Phoenix (Netzsch) from 0 resp. 20 to 300 °C with a heating rate of 10 K / min. Indium (Tm=156.6 °C), Tin (Tm=231.9 °C), Bismuth (Tm=271 .4 °C), were used as standards to calibrate the instrument.Specimen Fabrication

[0059] Specimens were printed with a commercially available SLA printer (Prusa SL1S). The exposure times were adjusted according to the anorganic filler content and varied between 28 and 55 s. The specimens were washed with isopropyl alcohol and dried with pressurized air. UV post-curing was performed in a UV-LED cube (LED Cube 100 1C Hbnle) for 60 s at 50 %. Thermal annealing was performed in a convection oven (Binder) at 200°C for 2h and let cool down to room temperature. Mechanical Testing

[0060] Tensile modulus, strain and stress at break were tested according to ISO 527-1 / -2 and 1BA geometries with speeds of 1 mm / min and 5 mm / min respectively on a tensile tester (Zwick ZwickiLine 2.5kN). The flexural modulus, flexural strength and stress at break were tested according to IPC-TM-650 with 1 % / min on a three point bending geometry on the above-mentioned Zwick ZwickiLine 2.5kN. The impact strength was measured according to ASTM D4812:2006 at room temperature and 1 J (Zwick Impact Tester).EXAMPLE I: EFFECT OF LOADING, SIZE AND SURFACE-MODIFICATION OF THE SILICA NANOPARTICLES ON THE VISCOSITY OF THE BASE RESIN

[0061] The viscosity of the base resin as a function of the loading, size and surfacemodification of the silica nanoparticles was measured with rotational rheometer. As can be seen in FIG. 6, and in the following table, the viscosity increases with increasing particle load. Furthermore, the presence of the silica nanoparticles increase the shear thinning behavior of the inks.

[0062] The non-modified nanoparticles led to viscosities >26000 mPas, which is far outside of the printable regime for SLA-printers.Table 1.

[0063] To be able to print test specimens 2 wt.% TPO-L was added as a photoinitiator. Based on the viscosity measurements the (acrylate) surface-modified nano-particles were added and specimens were printed for tensile test, bending and impact tests, as well as DMA and TMA measurements. Specimens for the thermogravimetric measurements were taken from the tensile test specimens.EXAMPLE II TGA MEASUREMENT

[0064] To measure the thermal decomposition and out-gasing of the printed specimens, a TGA was performed. As can be seen in FIG. 3, only marginal mass losses were measured below 250°C.

[0065] A significant mass loss started to occur for temperatures >325 °C. The mass loss at 250 °C as well as TD2, TDS and Toecomp. Are displayed in table 2:Table 2: Effect of BMI Concentration on (w / w) decomposition:

[0066] When switching to oxygen at temperatures >600°C the last of the remaining organic content decomposes, and only the inorganic silica particles remained at the respective weight percentages.

[0067] When comparing the decomposition temperatures of different bmi-methacrylate- concentrations, the improved thermal stability of the resin can be observed as illustrated in FIG. 7. While the shift is only minor in the lower concentrations, a larger increase is observed for concentrations between 30 and 50% (w / w) of BMI.EXAMPLE III THERMAL EXPANSION COEFFICIENT

[0068] To determine the thermal expansion coefficient (a), TMA measurements were performed. To release initial internal stresses, samples were heated to 300 °C. The thermal expansion coefficient was then determined in the first cool down ramp from 300 to -10 °C and in the second heat-up ramp to 300 °C. As it can be seen in FIG. 2A, a steady slope of the dimension change over the whole temperature range was observed.

[0069] With increasing filler content (namely silica beads, with acrylate surface modification (SFP130mod), the thermal expansion decreases from 97.5 ppm / K to 50.6 ppm / K for a temperature range of 35-230 °C.

[0070] As shown in Table 3:Table 3: Effect of particle loading on CTECTE [ppm / K]0-110 °C 110-200 °C 200-300 °C 35-230 °CBMI-SR834 25 / 75 2wt.% TPO-L 72.9 103.6 123.4 97.5BMI-SR834 25 / 75 + 48wt% 45.0 72.6 116.3 66.0SFP130mod 2wt.% TPO-LBMI-SR834 25 / 75 + 59wt% 36.1 54.7 62.3 50.6SFP130mod 2wt.% TPO-LEXAMPLE IV: MECHANICAL PROPERTIES:Thermo-mechanical Properties

[0071] To determine the mechanical properties of the material at elevated temperatures DMA measurements were performed at a temperature range from room temperature to 420 °C. As expected, the mechanical stability decreases steadily with increasing temperature reaching a sudden drop above 350 °C indicating the complete failure. Interestingly, a drop in the Youngs-Modulus indicating a glasstransition temperature cannot be observed (see e.g., FIG. 4).

[0072] The effect of BMI-acrylate-concentrations on the storage modulus (E) as a function of temperature was performed, and is illustrated in FIG. 8. As illustrated, pure acrylate (0% BMI) has an accelerated loss of stiffness from ~240°C on, while 10% and 20% BMI concentrations show improved thermal stability, and are ultimately crossed by the 0% curve. Although 30% to 50% BMI concentrations exhibit a steeper slope, still, and unlike the SR833S combination is observed (which is an acrylate that does not work in combination with the BMI), no glass-transition (Tg) can be observed.

[0073] Furthermore, as illustrated in FIG. 9, the excellent thermo-mechanical properties are also obtained not only with a photo-initiator content of 2% TPO-L but also with combinations of TPO- L (4%) and ethyl 4-(dimethylamino)benzoate (EDB, 2%) as well as TPO-L (1%) and phenyl- bis(2,4,6-trimethyl benzoyl) phosphine oxide (BAPO) (1%). The sudden loss in stiffness of the TPO- L&EDB sample can be attributed to a breaking of the sample.

[0074] Additionally, the influence of a thermal intiator 2,2'-Azobisisobutyronitrile (AIBN) with a concentration of 2% was investigated. As clearly illustrated in FIG. 10 the sample does not exhibit the onset of translation mobility expressed as glass transition temperature (Tg).

[0075] As further illustrated in FIG. 11, as an alternative to the BMI-689, the thermomechanical stability as expressed by the storage modulus E, was analyzed using a combination of BMI-1400 and SR834 (25wt% and 75wt% respectively) was investigated, again showing the arrest of the onset of translation mobility expressed as glass transition temperature (Tg).Differential Scanning Calorimetry (DSC)

[0076] As illustrated in FIG 12, neither the DSC signal (lower curve), nor the heat capacity Cp (top curve), show a discontinuity in the heat flow - typical of a glass transition temperature. The dip of the curves above 250 °C is related to a thermal degradation and thus mass loss of roughly 0.3 % at 300 °C as determined in the TGA measurements illustrated herein Discussion

[0077] The aliphatic, UV curable and thermally stable bismaleimide resin 1,6-bismaleimido- (2,2,4-trimethyl)hexane (MATMD, BMI-689) served as the basic component of the studied formulations in various contents. In addition to acrylate resins with high intrinsic glass transition temperatures or multi-functionalities, other resins and aromatic and high molecular weight BM1 resins were also used as a further component. The BMI-689 formulations with acrylate resins showed very homogeneous mixtures, while a formulation with the aromatic BMI could only be added at very small contents. The reactivity of all prepared formulations was investigated with the help of UV rheology. All systems showed a curing of the material under UV exposure. The test specimens were manufactured using the mSLA process and were successful for the formulations with acrylate content. Both UV and thermal curing of the specimens were carried out. The thermal and mechanical tests of the materials with BMI-689 and acrylate resins in different mixing ratios illustrated in FIG.s 5A-5C clearly showed the influence of the aliphatic BMI system. The higher the BMI content in the systems, the lower the values for the glass transition, the CTE and also flexural characteristics such as modulus, strength and strain. The acrylates with aromatic units in the structure showed high Tg values and the CTE below the Tg was low.

[0078] Not wishing to be bound by theory, is appears that due to the heterogeneous (BMI- Acrylate) network formed, no Tg could be measured for the systems with multifunctional acrylates;and the CTE values were also reduced. The flexural properties were also influenced by the flexible BMI-689.BMI-689 represented by the formula:

[0079] The lower the BMI content, the higher the flexural modulus, strength, and strain. The decomposition temperature was positively influenced by the addition of the BMI. Higher contents showed higher thermal stability over a long temperature range.1. Accordingly and in an exemplary implementation, provided herein is a method of substantially eliminating the onset of translational mobility of a polymer chain segment following phase change, over a predetermined temperature range, the method comprising forming a curable liquid composition comprising: admixing into a solution comprising a multifunctional acrylate polymer or its oligomer, a multifunctional crosslinking agent (MCA) and a photoinitiator (PI) at a predetermined volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA; and curing the curable liquid composition, thereby forming a cured polymer network, wherein the fractional concentration of the MCA in cured polymer network is configured to be above the three dimensional (3D) bond percolation threshold of the cured polymer network, wherein (i) the MCA has at least 3 functional ends, (ii) comprises a Bismaleimide (BMI) monomer represented by the formula: o oAA rO 0 where: - x is an aliphatic spacer, an aromatic spacer, or their combination, or (iii) wherein x is an aliphatic chain having the general formula (CH2)n, wherein n is an integer between 1 and 70, wherein(iv) the BMI is: a 4,4'-bismaleimidodiphenylmethane MDAB), and / or a 2,4-bismaleimidotoluene (TDAB), and / or (l,l-(methylenedi-4,l -phenylene) bismaleimide (MDPB), and / or bis(3-methyl-5- ethyl-4-maleimidophenyl) methane, and / or a 2,2-bis(4-maleimido phenoxyphenyl)propane, and / or (5,6-(diheptylen-phenylene) bismaleimide, and / or bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and / or m-xylylenebismaleimide (MXBI), and / or a 1,6- bismaleimido(trimethyl)hexane (MATMD), wherein (v) the volume ratio between the BMI and the acrylate polymer, or oligomer is between 1:10 and 11:20, wherein (vi) the acrylate polymer or oligomer is a multifunctional acrylate selected from the group comprising: 1 ,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,4- butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol-A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate, polyethylene glycol diacrylatc, trimcthylolpropanc triacrylatc, ethoxylated trimcthylolpropanc triacrylatc, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tris(2-acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, Tris (2-hydroxy ethyl) isocyanuratetriacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate or a multifunctional acrylate composition comprising one or more of the foregoing and their oligomers, wherein (vii) the photoinitiator is present in the liquid composition at a concentration of between 0.01% and 10%, and is selected from: ethyl(2,4,6, trimethyl benzoil) phenyl phosphinate), benzophenone and acetophenone compounds, mixed triarylsulfonium hexafluoroantimonate salts, 2- ispropylthioxanthone or a photinitiator composition comprising one or more of the foregoing, wherein (viii) the fractional volume concentration of the MCA in the cured polymer network is between about 8% and about 75% (v / v), (ix) the BMI is bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and the multifunctional acrylate is: Tris (2-hydroxy ethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate, at a BMI-to the multifunctional acrylate ratio of 1:3, and wherein (x) the predetermined temperature range is between -25 °C (248K) and 400 °C.2. In another exemplary implementation, provided herein is a curable dielectric ink composition configured, upon curing, to substantially eliminate the onset of translational mobility of a polymer’s chain, or its oligomer segment at a predetermined temperature range comprising: a multifunctional acrylate polymer or its oligomer; a multifunctional crosslinking agent (MCA); and aphotoinitiator (PI), wherein the volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA is between 1:10 and 11:20, wherein (xi) the fractional volume concentration of the MCA upon curing the curable dielectric ink composition, is between about 8% and about 75% (v / v), (xii) the MCA comprises a Bismaleimide (BMI) monomer represented by the formula:where: - x is an aliphatic spacer, an aromatic spacer, or their combination, and / or (xiii) x is an aliphatic chain having the general formula (CH )n, wherein n is an integer between 1 and 70, wherein (xiv) the BMI is: a 4,4'-bismaleimidodiphenylmethane (MDAB), and / or a 2,4-bismaleimidotoluene (TDAB), and / or (l,l-(methylenedi-4,l -phenylene) bismaleimide (MDPB), and / or bis(3-methyl-5-ethyl-4- maleimidophenyl) methane, and / or a 2,2-bis(4-maleimido phenoxyphenyl)propane, and / or (5,6- (diheptylen-phenylene) bismaleimide, and / or bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and / or m-xylylenebismaleimide (MXBI), and / or a 1,6- bismaleimido(trimethyl)hexane (MATMD), wherein (xv) the acrylate polymer or oligomer is a multifunctional acrylate selected from the group comprising: 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1 ,4-butanediol diacrylate, 1,6- hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol- A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tris(2-acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, Tris (2-hydroxy ethyl) isocyanuratetriacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipcntacrythritol pcntaacrylatc and dipcntacrythritol hcxaacrylatc or a multifunctiona acrylate composition comprising one or more of the foregoing and their oligomers, (xvi) the photoinitiator is present in the liquid composition at a concentration of between 0.01% and 10%, and is selected from: ethyl(2,4,6, trimethyl benzoil) phenyl phosphinate), benzophenone and acetophenone compounds, mixed triarylsulfonium hexafluoroantimonate salts, 2-ispropylthioxanthone or a photinitiator composition comprising one or more of the foregoing, wherein (xvii) the BMI is bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and the multifunctional acrylate is: Tris (2-hydroxyethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate, at a BMI-to the multifunctional acrylate ratio of 1:3, and (xviii) the predetermined temperature range is between -25 °C and 400 °C.

[0080] Although the foregoing disclosure for systems, methods and compositions for substantially eliminating the onset of translational critical chain length mobility of cured polymer, resulting in articles of manufacture exhibiting improved thermomechanical properties over large temperature ranges has been described in terms of some exemplary implementations, other exemplary implementations will be apparent to those of ordinary skill in the art from the disclosure herein. Moreover, the described exemplary implementations have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods, programs, libraries and systems described herein may be embodied in a variety of other forms without departing from the spirit thereof. Accordingly, other combinations, omissions, substitutions and modifications will be apparent to the skilled artisan in view of the disclosure herein.

Claims

What is claimed:

1. A method of substantially eliminating the onset of translational mobility of a polymer chain segment following phase change, over a predetermined temperature range, the method comprising forming a curable liquid composition comprising: a) admixing into a solution comprising a multifunctional acrylate polymer or its oligomer, a multifunctional crosslinking agent (MCA) and a photoinitiator (PI) at a predetermined volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA; and b) curing the curable liquid composition, thereby forming a cured polymer network, wherein the fractional concentration of the MCA in cured polymer network is configured to be above the three dimensional (3D) bond percolation threshold of the cured polymer network.2 The method of claim 1, wherein the MCA has at least 3 functional ends.3 The method of claim 2, wherein the MCA comprises a Bismaleimide (BMI) monomer represented by the formula:where: - x is an aliphatic spacer, an aromatic spacer, or their combination.4 The method of claim 3, wherein the BMI is at least one of: a 4,4'- bismaleimidodiphenylmethane MDAB), a 2,4-bismaleimidotoluene (TDAB), (l,l-(methylenedi-4,l- phenylene) bismaleimide (MDPB), bis(3-methyl-5-ethyl-4-maleimidophenyl) methane, a 2,2-bis(4- maleimido phenoxyphenyl)propane, (5,6-(diheptylen-phenylene) bismaleimide, bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, z -xylylenebismaleimide (MXBI), and a 1,6- bismaleimido(trimethyl)hexane (MATMD).5 The method of claim 3, wherein x is an aliphatic chain having the general formula (CH2)n, wherein n is an integer between 1 and 70.6 The method of claim 4, wherein the volume ratio between the BMI and the acrylate polymer, or oligomer is between 1:10 and 11 :20.7 The method of claim 6, wherein the acrylate polymer or oligomer is a multifunctional acrylate selected from the group comprising: 1 ,2-ethanediol diacrylate, 1,3 -propanediol diacrylate, 1 4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycoldiacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol-A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tris(2- acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, Tris (2-hydroxy ethyl) isocyanuratetriacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate or a multifunctional acrylate composition comprising one or more of the foregoing and their oligomers.8 The method of claim 7, wherein the photoinitiator is present in the liquid composition at a concentration of between 0.01 % and 10%, and is selected from: ethyl(2,4,6, trimethyl benzoil) phenyl phosphinate), benzophenone and acetophenone compounds, mixed triarylsulfonium hexafluoroantimonate salts, 2-ispropylthioxanthone or a photinitiator composition comprising one or more of the foregoing.9 The method of claim 3 wherein the fractional volume concentration of the MCA in the cured polymer network is between about 8% and about 75% (v / v).10 The method of claim 9, wherein the BMI is bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and the multifunctional acrylate is: Tris (2-hydroxy ethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate, at a BMI-to the multifunctional acrylate ratio of 1:3.11 The method of claim 1 , wherein the predetermined temperature range is between -25 °C (248K) and 400 °C.12 A curable dielectric ink composition configured, upon curing, to substantially eliminate the onset of translational mobility of a polymer’ s chain, or its oligomer segment at a predetermined temperature range comprising: a) a multifunctional acrylate polymer or its oligomer; b) a multifunctional crosslinking agent (MCA); and c) a photoinitiator (Pl), wherein the volume ratio (v / v) of the multifunctional acrylate polymer or its oligomer - to the MCA is between 1:10 and 11:20.

13. The curable dielectric ink composition of claim 12, wherein the fractional volume concentration of the MCA upon curing the curable dielectric ink composition, is between about 8% and about 75% (v / v).

14. The curable dielectric ink composition of claim 13, wherein the MCA comprises a Bismaleimide (BMI) monomer represented by the formula:where: - x is an aliphatic spacer, an aromatic spacer, or their combination.

15. The curable dielectric ink composition of claim 14, wherein the BMI is at least one of: a 4,4'- bismaleimidodiphenylmethane (MDAB), a 2,4-bismaleimidotoluene (TDAB), ( 1 , 1 -(methylenedi- 4 1 -phenylene) bismaleimide (MDPB), bis(3-methyl-5-ethyl-4-maleimidophenyl) methane, a 2,2- bis(4-maleimido phenoxyphen yl)propane, (5,6-(diheptylen-phenylene) bismaleimide, bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, m-xylylenebismaleimide (MXBI), and a 1,6- bismaleimido(trimethyl)hexane (MATMD).16 The curable dielectric ink composition of claim 15, wherein x is an aliphatic chain having the general formula (CI Iijn. wherein n is an integer between 1 and 70.17 The curable dielectric ink composition of claim 15, wherein the acrylate polymer or oligomer is a multifunctional acrylate selected from the group comprising: 1 ,2-ethanediol diacrylate, 1 3-propanediol diacrylate, 1 ,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol- A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylatc, propoxylated trimcthylolpropanc triacrylatc, propoxylated glycerol triacrylatc, tris(2- acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, Tris (2-hydroxy ethyl) isocyanuratetriacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate or a multifunctiona acrylate composition comprising one or more of the foregoing and their oligomers.

18. The curable dielectric ink composition of claim 17, wherein the photoinitiator is present in the liquid composition at a concentration of between 0.01% and 10%, and is selected from: ethyl(2,4,6, trimethyl benzoil) phenyl phosphinate), benzophenone and acetophenone compounds, mixed triarylsulfonium hexafluoroantimonate salts, 2-ispropylthioxanthone or a photinitiator composition comprising one or more of the foregoing.

19. The curable dielectric ink composition of claim 18, wherein the BMI is bis (1,2 maleimidoheptane) 5,6-diheptenyl cyclohexene, and the multifunctional acrylate is: Tris (2-hydroxy ethyl) isocyanuratetriacrylate, or Dipentaerythriolhexaacrylate, at a BMI-to the multifunctional acrylate ratio of 1:3.

20. The curable dielectric ink composition of claim 12, wherein the predetermined temperature range is between -25 °C and 400 °C.21 . An article of manufacture comprising the composition of any one of claims 12-20.

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