Reactive polyamideimide oligomers, methods and articles

Abstract

Reactive carboxylic acid ammonium salts, polyamide amic acid oligomers and polyamideimide oligomers are made of at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent. The crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group that can be chain extended and crosslinked after the reactive polyamideimide oligomer is formed. The number average molecular weight (M) of the reactive polyamide amic acid and polyamideimide oligomer is n ) is calculated using the Carothers equation to be about 1000 to about 10000 g / mol. Reactive carboxylic acid ammonium salts, polyamide amic acid oligomers and polyamide imide oligomers can be used in a variety of functional materials, manufacturing methods and articles.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 932,892, filed on November 8, 2019, and U.S. Provisional Application No. 63 / 075,610, filed on September 8, 2020, the disclosures of which are incorporated herein by reference in their entireties. Background Art

[0002] Fully aromatic polyamide-imide (PAI) is a high-performance polymer with alternating cyclic imide and amide bonds in the polymer backbone, which was first commercialized in the early 1970s. High molecular weight PAI has excellent high temperature strength, low temperature toughness and impact strength, as well as outstanding chemical resistance and dimensional stability. High molecular weight PAI can have unimidized amic acid groups in the polymer backbone. The amic acid groups impart some flexibility to the polymer backbone, which makes PAI melt-processable to some extent, but not easily. However, there are still several challenges associated with the melt processing of high molecular weight PAI. Melt viscosity is highly sensitive to temperature and shear rate, and the processing window of PAI is narrow, requiring processing temperatures above 600°F (316°C). Amic acid is thermally converted to imide by cyclodehydration, and the conversion of amic acid groups to cyclic imide groups results in a rapid increase in the rigidity of the polymer backbone, and therefore a rapid increase in melt viscosity. If this happens during extrusion, there is a risk that the polymer melt may solidify in the extruder. Due to the presence of unimidized amic acid groups, PAI is highly sensitive to moisture and must be thoroughly dried before melt processing and kept dry during melt processing to prevent molecular weight and thermo-mechanical property degradation. In addition, imidization and removal of imidized water at 500°F (260°C) for 20 days or more may be required to obtain optimal properties. These difficulties limit the use of high molecular weight PAI to the manufacture of simple stock shapes, such as rods, plates, tubes, and other profiles. These shapes can then be processed into parts that cannot be achieved by injection molding, such as turning, drilling, and milling steps.

[0003] In view of the processing limitations of high molecular weight PAI, injection molding grades with lower viscosity have been developed. These grades can be used to produce injection molded, filled and unfilled parts and profiles, but with great difficulty. Injection molding grades are considered to be mixtures of amine-terminated low molecular weight (oligo) polyamides with dianhydride chain extenders such as pyromellitic anhydride (PMDA) to build molecular weight in situ. The oligomeric nature of the polyamide reduces the melt viscosity, which facilitates the melt processing step, and the amine-terminated polyamide oligomer reacts with the dianhydride to form a high molecular weight polyamide amic acid intermediate through chain extension. After processing, the resulting parts and profiles require post-curing. In the post-curing, the amic acid groups cyclodehydrate to form PAI. A major disadvantage of this route to PAI is the need to remove a large amount of water from the final part. This water has two sources: i) physically adsorbed water associated with the hygroscopic residual amic acid moiety in the chain-extended PAI; ii) water generated in the cyclodehydration step. Removing water from parts and profiles is a time consuming process requiring programmed heating regimens from days to weeks, depending on the thickness of the part and its ultimate application. There is a need in the art for fully aromatic PAIs that do not require extended thermal post-curing and time consuming water removal steps.

[0004] Although injection molding grade PAI is an improvement over high molecular weight PAI, it still presents several challenges in melt processing. As mentioned above, the amic acid groups are still present in the chain-extended PAI, so it must be thoroughly dried before use. A thermal post-processing step is also required to complete the polymerization (chain extension) and / or imidization of the amic acid groups. As mentioned above, water is generated during these post-processing steps and must be removed to avoid foaming, microbubble formation, and part embrittlement. Injection molding grade PAI also presents other difficulties. Residence time must be optimized, as too long residence time will cause flow loss due to chain extension and increased viscosity. The mold must be filled quickly, and the pressure must be optimized for each mold size and shape. Injection molding with a family mold design does not work well. The viscosity of injection molding grade PAI is still highly shear sensitive. Therefore, injection speed, injection pressure, back pressure, screw speed, barrel temperature, cycle time, and mold heating must be optimized for each specific mold shape and size.

[0005] Post-heat treatment remains critical for injection-molded grade PAI. Although molded parts may appear finished, they are actually weak, brittle, have poor chemical and abrasion resistance, and suboptimal heat resistance. To achieve optimal properties, molded parts must be heated in a forced-air oven according to a curing schedule with a series of incremental temperature increases at certain intervals, which must be optimized for each type and size of part. The general curing schedule recommended by manufacturers is: 375℉(191℃) 1 day, 425℉(218℃) 1 day, 475℉(246℃) 1 day, and 500℉(260℃) 5 days, for a total of 8 days. Thicker parts may take longer to cure because the reacting water must diffuse out of the part to react. Therefore, the reaction rate decreases as the diffusion path is extended. In addition, some parts, such as those with very thin walls and / or delicate features, may need to be fixed during post-cure to meet tight dimensional tolerances.

[0006] In view of the above problems, this area still needs to be easy to melt-processed and curable PAI, which does not need extensive drying and does not need extensive thermal post-treatment to remove the water produced by the cyclodehydration of the amide acid functional group before processing. It is also necessary to be suitable for PAI of various product manufacturing processes, for example, for direct injection molding of complex shapes, for using continuous fibers to manufacture unidirectional tapes and fiber-reinforced composite materials, and for 3D printing applications, such as using fused deposition molding (FDM) of long filaments or rods, or powder bed printing, such as selective laser sintering (SLS). The subject matter described herein solves these shortcomings in this area and more fields. Summary of the invention

[0007] The reactive polyamideimide oligomer comprises units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed; wherein the reactive polyamideimide oligomer has a number average molecular weight (M) of about 1000 to about 10000 g / mol calculated using the Carothers equation. n ). "Derived from" means that the reactive polyamideimide oligomer is formed by step-growth polymerization of at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent, and by cyclodehydration of the resulting polyamide amic acid oligomer intermediate, with the formation of small molecules such as water and hydrochloric acid as by-products.

[0008] The method for preparing a reactive polyamideimide oligomer comprises: copolymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent in the presence of a polar solvent to form a reactive polyamide amic acid oligomer; and heating the reactive polyamide amic acid oligomer at a sufficient temperature and time to prepare the reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0009] Another method for preparing reactive polyamideimide oligomers comprises: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of an alcohol at a temperature and for a time sufficient to form at least one reactive carboxylic acid ammonium salt; optionally removing excess C 1-4 An alcohol; and heating a reactive carboxylic acid ammonium salt at a temperature and for a time sufficient to form a reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0010] The method of making an article includes heating the reactive polyamideimide oligomer at a temperature and time sufficient to form and crosslink the reactive polyamideimide oligomer. The method can be additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging. Also disclosed is an article made by the method.

[0011] The reactive polyamide amic acid oligomer comprises units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent, wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamide amic acid oligomer is formed; wherein the reactive polyamide amic acid oligomer has a number average molecular weight (M) of about 1000 to about 10000 g / mol calculated using the Carothers equation. n ).

[0012] The method for preparing reactive polyamide amic acid oligomers comprises: copolymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one cross-linkable monomer or cross-linkable end-capping agent in the presence of a polar solvent to form a reactive polyamide amic acid oligomer; wherein the cross-linkable monomer or cross-linkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamide amic acid oligomer is formed.

[0013] The method for making the article includes heating the reactive polyamide amic acid oligomer at a temperature and time sufficient to imidize, shape and crosslink the reactive polyamide amic acid oligomer. The method can be additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging. Also disclosed is an article made by the method.

[0014] The reactive ammonium carboxylate salt is formed by the following method: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of at least one of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; and removing excess water and C 1-4 alcohol; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

[0015] The method for preparing a reactive ammonium carboxylate salt comprises: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of at least one of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; and removing excess C 1-4 alcohol; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

[0016] The method for making an article comprises heating a reactive carboxylic acid ammonium salt at a temperature, pressure and time sufficient to make, shape and crosslink a reactive polyamideimide oligomer. The method can be fiber reinforced composite material manufacturing, pultrusion, compression molding, injection molding or solution casting. Also disclosed is an article made by the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Now refer to the accompanying drawings:

[0018] Figure 1 Depicted is an exemplary composite plate prepared as in Example 4. n =5000 g / mol, fully imidized, melt) was impregnated with four layers of carbon fiber fabric T650 and consolidated using a heated parallel plate press to prepare a composite plate.

[0019] Figure 2 A to 2D illustrate the concepts of cross-interface diffusion as well as chain entanglement and cross-linking across the interface. Figure 2 A and 2B depict the diffusion and entanglement of high molecular weight high performance thermoplastics. Figure 2 C and 2D depict the diffusion, entanglement, chain extension, and cross-linking of reactive oligomers.

[0020] Figure 3 This is a graph showing the relationship between the axial force (N) and time (min) during the melt polymerization of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, trimellitic anhydride and 4-(phenylethynyl)phthalic anhydride in a twin-screw extruder. DETAILED DESCRIPTION

[0021] Reactive polyamideimide oligomers and reactive polyamide amic acid oligomers (collectively referred to herein as "reactive oligomers"), reactive carboxylic acid ammonium salts, methods for making reactive oligomers and reactive carboxylic acid ammonium salts, methods for processing reactive oligomers and reactive carboxylic acid ammonium salts, and articles made from reactive oligomers and reactive carboxylic acid ammonium salts are disclosed herein. The approach to obtaining the polyamideimide articles described herein eliminates the need for extended thermal post-curing and time-consuming water removal steps. This is achieved by designing a fully imidized reactive polyamideimide oligomer that can be melt processed and then subjected to a short (up to a few hours) thermal post-curing to produce a high molecular weight polyamideimide by chain extension / cross-linking. The latter reaction occurs by incorporating carefully selected functional groups into the reactive polyamideimide oligomers. These functional groups remain unreacted during the oligomerization process and can then be used for thermal post-curing. During thermal post-curing, these functional groups can be polymerized (chain extension / cross-linking) via addition reactions without generating small molecule byproducts like water.

[0022] The reactive polyamideimide oligomers with unreacted functional groups described herein allow the production of profiles, complex parts for injection molding, 3D printed parts, and fiber or mineral reinforced composites without any thickness restrictions, because the step of removing water from the final product is no longer required. These routes to polyamideimide not only provide processing advantages (e.g., low viscosity, no residual water, no generated water), but also allow the design and manufacture of PAI articles that were previously impossible to manufacture.

[0023] With M in the range of about 1000 to about 10000 g / mol n Provides lower melt viscosity and lower processing temperature, so that conventional melt processing equipment can be used for melt processing. However, low molecular weight polymers (oligomers) are known to have poor mechanical properties because they lack polymer chain entanglement. The use of crosslinkable monomers and / or crosslinkable end-capping agents in the preparation of reactive oligomers can increase the molecular weight by in-situ thermal polymerization (e.g., during reaction injection molding) or during a thermal post-treatment step (e.g., when preparing fiber-reinforced composites).

[0024] Reactive polyamideimide oligomers having heat-curable groups have several advantages. Reactive polyamideimide oligomers are easily melt-processed, do not require extensive drying prior to processing, and do not require extensive thermal post-treatment. Complex parts can be made from reactive polyamideimide oligomers in one step. Curing can be carried out at about 300 to about 450°C and can be completed in as little as about 1 to about 60 minutes, compared to several days for currently available grades of PAI. When the reactive polyamideimide oligomer is fully imidized prior to melt processing, there is no need for the difficult step of removing water from the profile or injection molded part. Advantageously, the reactive polyamideimide oligomer can be used for one-step injection molding of complex parts under conditions where the reactive oligomer cures instantaneously. Alternatively, the part can be easily thermally cured for about 1 to about 60 minutes. In addition, the T of the cured reactive polyamideimide oligomer is g , elongation at break, breaking strength and toughness can be far superior to currently available PAI.

[0025] The reactive polyamideimide oligomer comprises units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed; and the number average molecular weight (M) of the reactive polyamideimide oligomer is n ) is calculated using the Carothers equation to be about 1000 to about 10000 g / mol.

[0026] The reactive polyamideimide oligomer comprises units derived from at least one aromatic diamine.The at least one aromatic diamine may have any chemical structure described below.

[0027]

[0028] In some aspects, the at least one diamine is at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine.

[0029] The reactive polyamide-imide oligomer also comprises at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent. The functional equivalent of carboxylic acid is a functional group in which the carboxyl carbon atom is in the same oxidation state, such as carboxylate, carboxylic acid halide and carboxylic anhydride. For example, the functional equivalent of trimellitic anhydride is a compound in which the substituent carbon atoms at 1-, 2- and 4-positions on the benzene ring are in the same oxidation state. The functional equivalent of trimellitic anhydride is 4-chloroformyl phthalic anhydride. At least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent includes at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent with ortho (ortho) carboxylic acid or functional equivalent group (such as phthalic anhydride group), so that a 5-membered phthalimide ring can be formed in the reactive oligomer skeleton. At least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent can have any chemical structure described below.

[0030]

[0031] In some embodiments, the at least one aromatic di-, tri-, or tetra-functional carboxylic acid or a functional equivalent thereof is at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride, or biphenyltetracarboxylic dianhydride.

[0032] The reactive polyamideimide oligomer also comprises at least one crosslinkable monomer or crosslinkable end-capping agent, which is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed. This functional group remains unreacted after the reactive polyamideimide oligomer is formed, and therefore can be used to participate in subsequent chain extension, branching and crosslinking reactions. Chain extension, branching and crosslinking occurring after the reactive polyamideimide oligomer is formed are collectively referred to as "curing". As used herein, "crosslinking" is also a shorthand for any combination of chain extension, branching and crosslinking. Curing or crosslinking can be initiated by heat, actinic (electromagnetic) radiation and electron beam radiation. In some embodiments, curing is thermally initiated. The unreacted functional groups participating in the subsequent chain extension, branching and crosslinking reactions are at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl or benzoxazine. These unreacted functional groups are described in Table 1 by chemical formula, chemical name and curing temperature range. At least one crosslinkable monomer or crosslinkable end-capping agent can be two crosslinkable monomers or crosslinkable end-capping agents having reactivity in different temperature ranges.

[0033] Table 1. Functional groups capable of thermal chain extension, branching, and crosslinking and cure temperature range.

[0034]

[0035]

[0036]

[0037] Examples of crosslinkable end-capping agents and crosslinkable monomers with names for unreacted functional groups are provided below. 1,2-diphenylacetylene is a crosslinkable monomer. All other compounds are crosslinkable end-capping agents. In some embodiments, the crosslinkable monomer or crosslinkable end-capping agent is at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA) or 4,4'-(acetylene-1,2-diyl) diphthalic anhydride.

[0038]

[0039]

[0040] The reactive polyamideimide oligomer may also contain units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, but has no unreacted functional groups capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed. The non-crosslinkable end-capping agent may be at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

[0041] The reactive polyamideimide oligomer can be linear or branched. In some embodiments, the reactive polyamideimide oligomer is branched. Branching is obtained by using a trifunctional monomer. Therefore, in some embodiments, the reactive polyamideimide oligomer also includes units derived from at least one of an aromatic triamine, an aromatic tricarboxylic acid, or an aromatic tricarboxylic acid chloride. An example of an aromatic triamine is 1,3,5-triaminobenzene, an example of an aromatic tricarboxylic acid is 1,3,5-benzenetricarboxylic acid, and an example of an aromatic tricarboxylic acid chloride is 1,3,5-benzenetricarboxylic acid chloride.

[0042] As used herein, the number average molecular weight M n is a target value, not a measured value. Using the Carothers equation, Eq. (2) calculates the amount of monomer and cross-linkable end-capping agent used to prepare the reactive oligomer. Eq. (1) is used to calculate the target Required degree of polymerization

[0043]

[0044]

[0045] (Also referred to as M n ) is a target number average molecular weight selected from the range of about 1000 to about 10000 g / mol) and is the average molecular weight of the repeating unit of the oligomer. and In the case of and substitute into Eq.2. Assuming the reaction is complete, so p = 1, this simplifies Eq.2 to an equation with one unknown r, which is the ratio of the reactants, and provides the required amount of energy to prepare the target The desired stoichiometric shift of the reactive oligomer.

[0046] Polyamide amic acid is an intermediate in the synthesis of polyamide imide. As shown in Scheme 1 below, polyamide imide is produced by cyclodehydration of the intermediate polyamide amic acid (upper right structure).

[0047] Solution 1

[0048]

[0049] Since polyamide amic acid is an intermediate for preparing polyamideimide, reactive polyamideimide oligomers can have different degrees of imidization, that is, polyamide amic acid intermediates are converted into polyamideimide. Therefore, in some embodiments, reactive polyamideimide oligomers are derived from reactive polyamide amic acid oligomer intermediates by dehydration cyclization, and the amic acid groups greater than about 80% and less than or equal to 100% in the reactive polyamide amic acid intermediate are imidized. When the imidization degree is within this range, reactive polyamideimide oligomers are considered to be "completely imidized". Within this range, polyamide amic acid groups greater than or equal to 85%, 90%, 95%, 96%, 97%, 98% and 99% and less than or equal to 100% can be imidized.

[0050] In some applications, less than 80% of the reactive polyamide-imide oligomers imidized may be useful. Therefore, in some embodiments, the reactive polyamide-imide oligomer is derived from the reactive polyamide amic acid oligomer intermediate by dehydration cyclization, and the amic acid groups greater than or equal to 20% and less than or equal to 80% in the reactive polyamide amic acid intermediate are imidized. Within this range, greater than or equal to 30%, 40%, 50%, 60% and 70% and less than or equal to 80% of the amic acid groups can be imidized.

[0051] Advantageously, the reactive polyamide oligomer has a melt complex viscosity of about 1000 to about 100000 Pa·s at 360° C., wherein the melt complex viscosity is calculated at N 2 The melt complex viscosity is measured by oscillatory shear rheology between parallel plates at a heating rate of 10 °C / min, a frequency of 2 rad / s, and strains of 0.03% to 1.0%. In this range, the melt complex viscosity is M n and at least one diamine, at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and a function of the type and relative amount of crosslinkable or non-crosslinkable monomers and end-capping agents used to make reactive polyamide oligomers. Therefore, the melt complex viscosity as a function of shear rate, time, temperature and heating rate can be adjusted by selecting monomers and reactive and non-reactive end-capping agents and their relative amounts. For example, the melt complex viscosity may be greater than or equal to 2000, 3000, 4000 or 5000 Pa s and less than or equal to 90000, 70000, 50000 or 30000 Pa s. In some embodiments, the melt complex viscosity is from about 5000 to about 30000 Pa s at 360 ° C. In contrast, it is reported that currently available PAI has a melt complex viscosity of 100000 Pa s at 2 radians / second.

[0052] The reactive polyamideimide oligomer can be made by a method comprising: copolymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and at least one crosslinkable monomer or crosslinkable end-capping agent in the presence of a polar solvent to form a reactive polyamide amic acid; heating the reactive polyamide amic acid oligomer at a sufficient temperature and time to prepare the reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed. The preparation of an exemplary reactive polyamideimide oligomer is provided in Scheme 2.

[0053] Solution 2

[0054]

[0055] A – Synthesis of reactive polyamideimide oligomers with only one cross-linkable end-capping agent;

[0056] B – Synthesis of reactive polyamideimide oligomers with two different cross-linkable end-capping agents;

[0057] C – Synthesis of reactive polyamideimide oligomers from dianhydrides (tetrafunctional) and diacids / diacid chlorides (difunctional) with only one crosslinkable end-capping agent;

[0058] D - Synthesis of reactive polyamideimide oligomers from crosslinkable monomers and non-crosslinkable end-capping agents; and

[0059] E - Synthesis of reactive polyamideimide oligomers from crosslinkable monomers and crosslinkable endcapping agents.

[0060] The sufficient temperature and time for preparing the reactive polyamideimide oligomer is about 140°C to about 220°C for about 1 minute to about 120 minutes. As described above, the reactive polyamideimide oligomer is manufactured by forming a reactive polyamide amic acid oligomer intermediate. The temperature and time required for imidizing the reactive polyamide amic acid oligomer intermediate in this method depend on whether there is a polar solvent, the specific reactive polyamideimide oligomer prepared, and the desired degree of imidization. When imidization is carried out in the absence of a solvent, that is, using a pure solid reactive polyamide amic acid oligomer, the sufficient temperature and time for preparing the reactive polyamideimide oligomer is about 220°C to about 300°C for about 1 minute to about 120 minutes. When imidization is carried out in the presence of a polar solvent, the sufficient temperature and time for preparing the reactive polyamideimide oligomer is about 140°C to about 220°C for about 1 minute to about 120 minutes.

[0061] The reactive polyamide-imide oligomer is manufactured in the presence of a polar solvent, which reduces the temperature range sufficient to prepare the reactive oligomer. The boiling point of the polar solvent at one atmosphere should be at least 150°C. The polar solvent can be at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or cyclopentane. In some embodiments, the polar solvent is N-methyl-2-pyrrolidone. The manufacturing method may also include removing the polar solvent from the polyamide-amic acid oligomer before heating the reactive polyamide-amic acid oligomer to a temperature and time sufficient to prepare the reactive polyamide-imide oligomer.

[0062] There are different methods for the imidization of reactive polyamide amic acid oligomers. Reactive polyamide imide oligomers can be prepared by adding toluene to the reactive polyamide amic acid oligomers and azeotropically distilling toluene with water. Reactive polyamide imide oligomers can also be prepared by microwave irradiation of reactive polyamide amic acid oligomers. The imidization agent can be acetic anhydride. Acidic byproducts are produced by imidization, such as acetic acid when acetic anhydride is used. Therefore, a base, such as a tertiary amine, can be used. The tertiary amine can be, for example, pyridine or triethylamine. Therefore, in some embodiments, reactive polyamide imide oligomers are prepared by heating reactive polyamide amic acid oligomers in the presence of acetic anhydride and a catalytic amount of a tertiary amine.

[0063] Another method for making reactive polyamideimide oligomers is to copolymerize in the presence of a phosphorylating agent and a catalytic amount of a salt. In this method, the di-, tri- or tetra-functional carboxylic acid or its functional equivalent does not include an acyl halide, such as an acyl chloride. The advantage of this method is that no expensive acyl chloride is required as a starting material. For example, in the presence of triphenyl phosphite, a polar solvent such as NMP as a solvent and a catalytic amount of a salt such as LiCl or CaCl 2 Copolymerization is carried out in the presence of pyridine. Heating to 120°C under nitrogen for 1.5 to 2 hours results in the formation of reactive polyamide amic acid oligomers and partial imidization to the corresponding reactive polyamide imide oligomers. Further heating to 150°C for up to 5 hours with additional pyridine under nitrogen provides complete imidization.

[0064] Reactive polyamideimide oligomers can also be prepared by reactive extrusion. Thus, the method of making reactive polyamideimide oligomers comprises reactively extruding at least one aromatic diamine or an activated derivative thereof (e.g., diacetylated diamine), at least one aromatic di-, tri-, or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent at a temperature and time sufficient to prepare the reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri-, or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0065] Reactive extrusion can be carried out in the presence of a polar solvent. The polar solvent can be at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane. In some embodiments, the polar solvent is N-methyl-2-pyrrolidone. The polar solvent can dissolve the monomer, or it can partially dissolve the monomer and form a fluid suspension or slurry of the monomer together with the oligomers and intermediates formed during the reactive extrusion.

[0066] Reactive extrusion can be carried out in the presence of an acid catalyst to promote the imidization (cyclodehydration) of the amide acid intermediate. When in liquid state under the reaction extrusion conditions, the acid catalyst can also partially dissolve the monomer and form a fluid suspension or slurry of the monomer together with the oligomers and intermediates formed during the reaction extrusion. When the acid catalyst is liquid, it can be removed by distillation through the vent during the reaction extrusion. In some embodiments, the acid catalyst is acetic acid, and it is removed by distillation during the reaction extrusion. Reactive extrusion can also be carried out in the presence of acetic anhydride, wherein acetic anhydride is removed by distillation during the reaction extrusion. In order to promote the removal of any water, HCl, polar solvents, acid catalysts and acetic anhydride present or produced, the reaction extrusion can be carried out in a melt extruder, and the melt extruder has a plurality of preset heating zones equipped with vents or other devices for removing these volatiles.

[0067] The reactive polyamideimide oligomer can also be made by the "ammonium carboxylate" method. The ammonium carboxylate method comprises: reacting a polyamideimide oligomer in water or C at a temperature and time sufficient to form at least one reactive ammonium carboxylate. 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent in the presence of at least one of the following: removing excess water and C 1-4 alcohol; and heating the reactive carboxylic acid ammonium salt at a temperature and for a time sufficient to form a reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed. 1-4 The alcohol may be, for example, at least one of methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, sec-butanol, or tert-butanol. 1-4 The alcohol is at least one of methanol or ethanol. The preparation of an exemplary reactive polyamideimide oligomer by the ammonium carboxylate salt method is described in Scheme 3 below.

[0068] Solution 3

[0069]

[0070] The anhydride and diamine were reacted in C 1-4 The reaction mixture is heated in an alcohol (e.g. methanol or ethanol) at 70°C for 1 hour. This will cause the anhydride to ring-open and form the corresponding dicarboxylic acid alkyl half ester, such as methyl or ethyl half ester. The solvent is then removed by vacuum distillation. The reactive carboxylic acid ammonium salt is therefore Ar-COO - and + H 3A mixture of all possible combinations of N-Ar, wherein Ar represents an aromatic group, and wherein Ar-COO - It is C 1-4 Alkyl half esters. Ammonium carboxylate salts (similar to nylon salts) can be converted into reactive polyamideimide oligomers by polymerization and imidization, which can be accomplished in a variety of ways. Polymerization and imidization can be carried out by heating the dried reactive ammonium carboxylate salt in an inert atmosphere, preferably heated to 300°C under pressure (0 to 300 MPa) to obtain reactive polyamideimide oligomers. (Option 1 in Scheme 3) The heating can be carried out in a sealed container (Option 1 in Scheme 3) and / or in an extruder with exhaust capability for removing water and methanol or ethanol vapor. (Option 2 in Scheme 3) For example, the reactive ammonium carboxylate salt can be gradually heated at 60, 100 and 200°C in a sealed container under an inert atmosphere for 1 hour, then cooled to 25°C, and then oligomerized at 320 to 360°C in an extruder to obtain a reactive polyamideimide oligomer. Therefore, in some embodiments, the method includes reactively extruding a reactive ammonium carboxylate salt at a temperature and time sufficient to form a reactive polyamideimide oligomer. Polymerization and imidization can also be carried out by dissolving the reactive carboxylic acid ammonium salt in at least one polar solvent, such as water, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane, and then heating to 160° C. (Option 3 in Scheme 3) Therefore, in some embodiments, the method includes dissolving the reactive carboxylic acid ammonium salt in a polar solvent and then heating at a temperature, pressure, and time sufficient to form a reactive polyamideimide oligomer.

[0071] Alternatively, at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least one crosslinkable monomer or crosslinkable endcapping agent may be mixed with water, methanol, ethanol, a methanol / water mixture or an ethanol / water mixture and then heated to 220° C. in a pressure vessel (bomb calorimeter or autoclave) to polymerize and imidize the reactive carboxylic acid ammonium salt.

[0072] Advantageously, the reactive carboxylic acid ammonium salt has a melt complex viscosity of about 1 to about 100 Pa.s in a temperature range of about 80 to about 120° C., and a solubility of up to 70 to 80 wt % in a polar solvent such as NMP at 60° C. The low melt complex viscosity and high solubility of the reactive carboxylic acid ammonium salt allow for high yield production of reactive polyamideimide oligomers.

[0073] Reactive polyamideimide oligomers can be used to prepare various functional materials with useful properties. Therefore, the mixture composition comprises reactive polyamideimide oligomers and thermoplastic polymers. For example, reactive polyamideimide oligomers and reactive polyamide amic acid oligomers can be used as plasticizers or reactive diluents to improve the processing properties of high molecular weight PAI polymers and other high molecular weight polymers. Compared with high molecular weight PAI, the reactive oligomers added to the PAI polymer can shorten the compression molding cycle by improving fluidity and improving consolidation (minimizing voids).

[0074] Another example of a functional material is a powder coating composition comprising a reactive polyamideimide oligomer. The reactive polyamideimide oligomer in powder form can be used to prepare coatings on various substrates, such as metals, ceramics, glass, and composite substrates. Powder coatings can be applied using thermal spraying, vacuum plasma spraying, and cold spraying techniques.

[0075] Another example of a functional material is a reactive adhesive composition comprising a reactive polyamideimide oligomer. The reactive adhesive composition in powder form can be applied to a variety of substrates (with or without pretreatment), melted, and cured under pressure at temperatures of 350 to 400°C. Substrates include glass, titanium, steel, and any material that can withstand high temperature curing. The active powder can be mixed with inert spherical fillers to control the thickness of the bonding layer (e.g., glass beads). The reactive adhesive can also be melted into a fabric to make a reactive tape that can be placed between two substrates, heated, and cured under pressure.

[0076] Another example of a functional material is a high temperature elastomer composition made by heating a reactive polyamideimide oligomer at a temperature and for a time sufficient to crosslink the reactive polyamideimide oligomer. Parts made from neat, filled or fiber reinforced crosslinked parts can be used as high temperature elastomers for sealant and gasket applications.

[0077] Another example of a functional material is a high temperature foam comprising a reactive polyamideimide oligomer.

[0078] In order to improve physical properties, it may be necessary to compound reactive polyamideimide oligomer with other materials. Therefore, the method for synthesizing reactive polyamideimide oligomer is included in the temperature and time sufficient to melt reactive polyamideimide oligomer but not cross-link reactive polyamideimide oligomer and reactive polyamideimide oligomer is mixed with at least one other material. The material can be at least one polymer, filler or additive. For example, reactive polyamideimide oligomer can be compounded with other reactive polyamideimide oligomer and / or reactive polyamide amic acid oligomer, to improve thermomechanical properties. Reactive polyamideimide oligomer can also be used for preparing block copolymer with other reactive polyamideimide oligomer and / or reactive polyamide amic acid oligomer, to improve thermomechanical properties.

[0079] Reactive oligomers can be used to make a variety of articles or parts with useful properties. Therefore, the method of making an article includes heating the reactive polyamideimide oligomer at a temperature and time sufficient to shape and crosslink the reactive polyamideimide oligomer. The temperature and time sufficient to shape and crosslink the reactive oligomer are about 300 to about 450° C. for about 1 to about 60 minutes. Exemplary curing conditions are about 350 to about 400° C. for about 30 to about 60 minutes, for example, about 360° C. for about 45 minutes.

[0080] For example, the manufacturing method can be additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging.

[0081] Also disclosed are articles made by the method. Various methods of making and articles made by the method are described below.

[0082] The manufacturing method may be a fiber reinforced composite material manufacturing. The reactive polyamide-imide oligomer may be present in a film powder. Therefore, the fiber reinforced composite material manufacturing may include heating at least one layer of fiber fabric and at least one layer of reactive polyamide-imide oligomer into a powder or film at a temperature, pressure and time sufficient to melt the reactive polyamide-imide oligomer, impregnating the fiber fabric, and cross-linking the reactive polyamide-imide oligomer to form a fiber reinforced composite material.

[0083] The reactive polyamideimide oligomer can also be dissolved in a polar solvent. Thus, the fiber reinforcement manufacturing method can include impregnating at least one layer of fiber fabric with a solution of the reactive polyamideimide oligomer dissolved in a polar solvent; removing the polar solvent under reduced pressure; and heating at a temperature, pressure, and time sufficient to crosslink the reactive polyamideimide oligomer and form a fiber reinforced composite material. For example, the fiber can be carbon fiber, glass fiber, cellulose (wood fiber / paper fiber, straw), polyamine (polyterephthalamide), polybenzoxazole (PBO) or polybenzimidazole (PBI).

[0084] A fiber reinforced composite material made by any of the above methods is also disclosed. For example, the composite material can be a multilayer carbon reinforced composite material. The multilayer reinforced composite material can have any number of layers, but in some embodiments, the number of layers is greater than or equal to 2 layers and less than or equal to 1000 layers.

[0085] The manufacturing method may be pultrusion for making unidirectional tapes. As with fiber reinforced composite manufacturing, pultrusion may be from a melt or solution of a reactive polyamideimide oligomer in a polar solvent. Also disclosed is a unidirectional tape prepared by pultrusion. The unidirectional (UD) tape may be a regular tape, a slit tape, a roving, or a pull tape. The UD tape may be used in automated tape laying technology / TOW manipulators for manufacturing fiber reinforced composites.

[0086] The manufacturing method can be solution spinning or melt spinning fiber. Also disclosed is a fiber manufactured by solution spinning or melt spinning. Reactive polyamide amic acid oligomer and M n Reactive polyamidoamine oligomers of about 10000 g / mol can be spun into fibers from solution or melt. In solution spinning, reactive oligomers dissolved in a suitable polar solvent or polar solvent mixture (e.g., NMP, DMAc, DMF, or NMP / THF) can be spun into fibers using a standard solution spinning apparatus (including a plunger pump and a spinneret operating at 25°C to 80°C). Fibers are obtained after coagulation in a non-solvent (e.g., water / acetone at -10°C to 60°C). The resulting fibers are dried and heated to induce imidization and crosslinking. It is also possible to dry the nascent fibers using a hot air stream, followed by an additional heating step. During the heat treatment, the fibers can be exposed to a stretching step, which increases the alignment of the polymer chains along the stretching direction, thereby increasing the fiber strength. In melt spinning, reactive polyamideimide oligomers are melted and spun into fibers by a spinning apparatus comprising a plunger pump, a heated resin chamber (250°C to 300°C), and a heated spinneret operating at 300°C to 400°C to induce crosslinking. The hot drawn fibers can be cooled (air / water) and wound up, and then subjected to a second heating step with or without post-drawing to complete crosslinking and increase fiber strength.

[0087] The method of manufacturing can be additive manufacturing. Also disclosed are articles manufactured by additive manufacturing. In some embodiments of additive manufacturing, the method is fused filament manufacturing. Fused filament manufacturing comprises extruding reactive polyamideimide oligomers in adjacent horizontal layers such that interfaces exist between the layers of polyamideimide oligomers, and exposing the layers to heat at a temperature and for a time sufficient to crosslink the reactive polyamideimide oligomers and form an article. Also disclosed are articles manufactured by fused filament manufacturing.

[0088] Fused filament fabrication uses material extrusion to print articles, where the feedstock is pushed through an extruder. In most fused filament fabrication 3D printers, the feedstock comes in the form of a filament wound on a spool. The 3D printer liquefier is the main component used in this type of printing. The extruders of these printers have a hot end and a cold end. The "cold" end is cooler than the hot end, but can still be in the temperature range of 100 to 250°C. The cold end pulls the material from the spool using a gear- or roller-based torque applied to the material and controlling the feed rate via a stepper motor. The cold end pushes the feedstock into the hot end. The hot end consists of a heating chamber and a nozzle. The heating chamber houses the liquefier, which melts the feedstock to convert it into a molten state. It allows the molten material to exit from a small nozzle, forming a thin, sticky bead of plastic that adheres to the material it is laying on. The diameter of the nozzle is usually between 0.3 mm and 1.0 mm. Different types of nozzles and heating methods are used depending on the material to be printed.

[0089] The filament can be in the form of a thin wire wound on a spool. In a variation of this method, the feedstock is in the form of a rod rather than a filament. Since the rod is thicker than the filament, it can be pushed toward the hot end by a piston or drum, exerting greater force and / or speed than conventional fused wire manufacturing.

[0090] The weld line is defined as the planar interface between adjacent extruded material layers. The reactive polyamideimide oligomer diffuses across the interface and reacts to rapidly increase polymer chain entanglement and network formation across the interface, fusing the adjacent layers together. The weld line (interface) is further strengthened by chain extension and / or cross-linking of the reactive polyamideimide oligomer entangled across the interface, thereby increasing z-axis strength.

[0091] By using reactive polyamideimide oligomers with two different reactive end groups, chain entanglement, network formation, chain extension and crosslinking processes in melt filament manufacturing can be optimized. Oligomer chains containing first unreacted functional groups with a first curing temperature can be first crosslinked to fix the printed structure in place. Oligomer chains containing second unreacted functional groups with a second curing temperature higher than the first curing temperature can diffuse at the interface and cure at the second curing temperature to form the molecular weight, crosslinking density and strength of the part.

[0092] In some embodiments of additive manufacturing, the method is selective laser sintering. Selective laser sintering includes selectively sintering and cross-linking particles of reactive polyamideimide oligomers or compositions thereof with a laser to form an article. Articles manufactured by selective laser sintering are also disclosed. Selective laser sintering (SLS) involves using a high-power laser (e.g., a carbon dioxide laser) to melt small particles of plastic, metal, ceramic, or glass powder into a substance having a desired three-dimensional shape. The laser selectively melts the powdered material by scanning a cross-section generated by a 3D digital description of the part on the surface of the powder bed (e.g., from a CAD file or scanned data). After scanning each cross-section, the powder bed is lowered by one layer of thickness, and then a new layer of material is applied on top, and the process is repeated until the part is completed. The SLS machine preheats the bulk powder material in the powder bed to a temperature below the powder flow point to make it easier for the laser to raise the temperature of the selected area to a temperature at which the powder softens and melts together.

[0093] In some embodiments of additive manufacturing, the manufacturing method is directed energy deposition (DED) or laser engineered net shaping (LENS). The present invention also discloses articles manufactured by DED and LENS.

[0094] Compared to some other additive manufacturing processes such as stereolithography (SLA) and fused filament fabrication (FFF), which most often require special support structures to manufacture overhanging designs, SLS does not require a separate feeder for support material because the part being built is always surrounded by unsintered powder, which allows the construction of previously impossible geometries. In addition, because the machine's chamber is always full of powder material, the manufacture of multiple parts has a much smaller impact on the overall difficulty and price of the design, because through a technique called "nesting", multiple parts can be positioned to fit within the boundaries of the machine.

[0095] In additive manufacturing methods such as FFF and SLS using reactive polyamideimide oligomers as raw materials, the oligomers diffuse through the particle or filament interface and interact to rapidly increase the entanglement of polymer chains at the particle or filament interface, thereby fusing adjacent particles or filaments together. The interface is further strengthened by chain extension and cross-linking of the reactive polyamideimide oligomers entangled across the interface.

[0096] Figure 2 A to 2D further illustrate the concepts of cross-interface diffusion and cross-interface chain entanglement and cross-linking. Figure 2 In each of A and 2D, the oligomer or polymer on the left is in a solid state, and the oligomer or polymer on the right is in a molten state. Figure 2 A depicts high molecular weight, high performance thermoplastics on either side of the interface. High molecular weight polymers can diffuse through the interface in both directions and form Figure 2The chain entanglement depicted in B. However, above T g But lower than T m A longer thermal annealing time (hours) is required at a temperature.

[0097] Figure 2 C depicts the reactive oligomers on either side of the interface. Low molecular weight reactive oligomers are g But lower than T m The diffusion across the interface is faster in both directions and forms Figure 2 Chain entanglement depicted in D. This rapid diffusion leads to a reduction in thermal annealing time. Chain extension and cross-linking can also occur through unreacted functional groups. The net effect of faster diffusion, chain entanglement, and chain extension and cross-linking is an increase in interlayer strength, i.e., an increase in z-axis strength in FFF and SLS.

[0098] As with fused filament fabrication, in selective laser sintering, the processes of chain entanglement, network formation, chain extension, and crosslinking can be further enhanced by using reactive polyamideimide oligomers with two different reactive end groups. Oligomer chains containing a first unreacted functional group with a first curing temperature can first be crosslinked to fix the printed structure in place. Oligomer chains containing a second unreacted functional group with a second curing temperature higher than the first curing temperature can diffuse at the interface and cure at the second curing temperature to form the molecular weight, crosslinking density, and strength of the part.

[0099] The manufacturing method may be solution casting. The solution casting includes: casting a reactive polyamideimide oligomer solution dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive polyamideimide oligomer film; and heating the polyamideimide oligomer film at a temperature and for a time sufficient to crosslink the polyamideimide oligomer and form a flexible film. A flexible film prepared by solution casting of the reactive polyamideimide oligomer is also disclosed.

[0100] The manufacturing method may also be injection molding. Also disclosed are articles manufactured by injection molding the reactive polyamideimide oligomer.

[0101] As mentioned above, reactive polyamide amic acid oligomer is an intermediate for producing reactive polyamide amino oligomer. Therefore, reactive polyamide amic acid oligomer comprises a unit derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable end-capping agent, wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamide amic acid oligomer is formed; wherein the reactive polyamide amic acid oligomer calculated using the Carothers equation has a number average molecular weight (M) of about 1000 to about 10000 g / mol. n ). Reactive polyamideimide oligomers and reactive polyamideamic acid oligomers are closely related because reactive polyamideamic acid oligomers are intermediates in the formation of corresponding reactive polyamideamine oligomers. They differ only in the degree of imidization. Although reactive polyamideimide oligomers as defined herein may have greater than 20% and less than or equal to 100% amic acid groups in the imidized reactive polyamideimide acid intermediate, in reactive polyamideimide acid oligomers as defined herein, 0% to about 20% of the imidic acid groups are imidized.

[0102] The component description applicable to the reactive polyamideimide oligomer disclosed herein is also applicable to the reactive polyamide amic acid oligomer. Thus, the aromatic diamine can be at least one of 1,3-phenylenediamine, 4,4'oxydiphenylamine or 3,4'oxydiphenylamine, and the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent can be trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic chloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride. The unreacted functional groups participating in the subsequent chain extension, branching and crosslinking reactions can be at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl or benzoxazine. Table 1 gives the chemical formula, chemical name and curing temperature range of these unreacted functional groups. The at least one crosslinkable monomer or crosslinkable end-capping agent may be two crosslinkable monomers or crosslinkable end-capping agents that are reactive at different temperature ranges. In some embodiments, the crosslinkable monomer or crosslinkable end-capping agent is at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA), or 4,4' (acetylene 1,2-diacyl) diphthalic anhydride.

[0103] The reactive polyamide amic acid oligomer may further comprise units derived from at least one non-crosslinking end-capping agent, wherein the non-crosslinking end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, but has no unreacted functional groups capable of chain extension and crosslinking after the reactive polyamide imide oligomer is formed. The non-crosslinking end-capping agent may be at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

[0104] Reactive polyamide amic acid oligomers can be manufactured by the following method: in the presence of a polar solvent, at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one cross-linkable monomer or cross-linkable end-capping agent are copolymerized to form reactive polyamide amic acid; wherein the cross-linkable monomer or cross-linkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamide amic acid oligomer is formed.

[0105] The reactive polyamide amic acid oligomer is made in the presence of a polar solvent, which reduces the temperature range sufficient to prepare the reactive oligomer. The polar solvent should have a boiling point of at least 150° C. at one atmosphere of pressure. The polar solvent can be at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, or cyclopentane. In some embodiments, the polar solvent is N-methyl-2-pyrrolidone. In some embodiments, the method further includes separating the reactive polyamide amic acid oligomer from the polar solvent.

[0106] Like the related reactive polyamide amine oligomers, reactive polyamide amic acid oligomers can be used to prepare various functional materials with useful properties. Therefore, the mixture composition comprises reactive polyamide amic acid oligomers and thermoplastic polymers. For example, reactive polyamide amic acid oligomers can be used as plasticizers or reactive diluents to improve the processing properties of high molecular weight PAI polymers and other high molecular weight polymers. Compared with high molecular weight PAI, the reactive oligomers added to the PAI polymer can shorten the compression molding cycle by improving fluidity and improving consolidation (minimizing the gap).

[0107] Other examples of functional materials including the reactive polyamide amic acid oligomer include powder coating compositions, reactive adhesive compositions, and high temperature foams.

[0108] It may be necessary to compound the reactive polyamide-amic acid oligomer with other materials. The method of compounding the reactive polyamide-amic acid oligomer includes mixing the reactive polyamide-amic acid oligomer with at least one other material at a temperature and time sufficient to melt but not crosslink the reactive polyamide-amic acid oligomer. The material can be at least one polymer, filler or additive.

[0109] Like reactive polyamide amide oligomers, reactive polyamide amic acid oligomers can be used to make various articles or parts with useful properties. Therefore, the method of making the article includes heating the reactive polyamide amic acid oligomer at a temperature and time sufficient to imidize, shape and crosslink the reactive polyamide amic acid oligomer. The temperature and time sufficient to imidize, shape and crosslink the reactive polyamide amic acid oligomer are about 1 to about 60 minutes at about 300 to about 450°C. Exemplary curing conditions are about 350 to about 400°C for about 30 to about 60 minutes, for example, about 360°C for about 45 minutes.

[0110] For example, the manufacturing method can be additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging.

[0111] Also disclosed are articles made by the method. Various methods of making and articles made by the method are described below.

[0112] The manufacturing method can be a fiber reinforced composite material manufacturing. The reactive polyamide amic acid oligomer can be a powder in the form of a film. Therefore, the fiber reinforced composite material manufacturing can include heating at least one layer of fiber fabric and at least one layer of reactive polyamide amic acid oligomer to powder or film at a temperature, pressure and time sufficient to imidize the reactive polyamide amic acid oligomer, impregnating the fiber fabric, and crosslinking to form a fiber reinforced composite material.

[0113] Reactive polyamide amic acid oligomers can also be dissolved in polar solvents. Therefore, the fiber-reinforced manufacturing method can include: impregnating at least one layer of fiber fabric with a reactive polyamide amic acid oligomer solution dissolved in a polar solvent; removing the polar solvent under reduced pressure, and heating at a temperature, pressure and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer to form a fiber-reinforced composite material. For example, the fiber can be carbon fiber, glass fiber, cellulose (wood fiber / paper fiber, straw), polyamine (polyterephthalamide), polybenzoxazole (PBO) or polybenzimidazole (PBI).

[0114] The present invention also discloses a fiber reinforced composite material, which is made of a reactive polyamide amic acid oligomer by any of the above methods. For example, the composite material can be a multilayer carbon reinforced composite material. The multilayer reinforced composite material can have any number of layers, but in some embodiments, the number of layers is greater than or equal to 2 layers and less than or equal to 1000 layers.

[0115] The manufacturing method may be pultrusion for making unidirectional tapes. As with fiber reinforced composite manufacturing, pultrusion may be from a melt or solution of a reactive polyamide amic acid oligomer in a polar solvent. Also disclosed is a unidirectional tape prepared by pultrusion. The unidirectional (UD) tape may be a regular tape, a slit tape, a roving, or a pull tape. The UD tape may be used in automated tape laying technology / TOW robots for manufacturing fiber reinforced composites.

[0116] The manufacturing method may be solution spinning or melt spinning of the reactive polyamide amic acid oligomer fiber. Also disclosed is a fiber manufactured by solution spinning or melt spinning of the reactive polyamide amic acid oligomer.

[0117] The manufacturing method may be additive manufacturing. The present invention also discloses articles made by additive manufacturing. In some embodiments of additive manufacturing, the method is fused filament manufacturing. Fused filament manufacturing includes extruding reactive polyamide amine amic acid oligomers in adjacent horizontal layers so that there is an interface between each layer of reactive polyamide amine amic acid oligomers, and exposing each layer to heat at a temperature and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomers and form the article. Also disclosed are articles made by fused filaments of reactive polyamide amic acid oligomers.

[0118] In some embodiments of additive manufacturing, the method is selective laser sintering. Selective laser sintering includes selectively sintering, imidizing and cross-linking reactive polyamide amic acid oligomer particles with a laser to form an article. Also disclosed are articles made by selective laser sintering reactive polyamide amic acid oligomers.

[0119] In some embodiments of additive manufacturing, the manufacturing method is directed energy deposition (DED) or laser engineered net shaping (LENS). Also disclosed are articles made by DED and LENS of reactive polyamide amic acid oligomers.

[0120] The manufacturing method may be solution casting. The solution casting includes: casting a reactive polyamide amic acid oligomer solution dissolved in a polar solvent onto a mold; removing the solvent to form a reactive polyamide amic acid oligomer film; and heating the reactive polyamide amic acid oligomer film at a temperature and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer and form a flexible film. A flexible film prepared by solution casting of a reactive polyamide amic acid oligomer is also disclosed.

[0121] The manufacturing method may also be injection molding. Also disclosed is an article manufactured by injection molding the reactive polyamide amic acid oligomer.

[0122] The manufacturing method may also be blow molding. The invention also discloses a product manufactured by blow molding of the reactive polyamide amic acid oligomer.

[0123] The above article discusses the "ammonium carboxylate" method for making reactive polyamideimide oligomers. The first step of the method is to form a reactive ammonium carboxylate salt. As an intermediate for making reactive polyamideimide oligomers, the reactive ammonium carboxylate salt itself is a useful composition. Therefore, the present invention discloses a reactive ammonium carboxylate salt, which is formed by the following method: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt, for example, from about 50° C. to about 150° C. for about 30 minutes to about 8 hours; removing excess C 1-4 wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt. For example, C 1-4 The alcohol may be at least one of methanol, ethanol, 1-propanol, isopropanol, 1-butanol, isobutanol, sec-butanol, or tert-butanol. 1-4 The alcohol is at least one of methanol or ethanol.

[0124] Reactive carboxylic acid ammonium salts are related to the reactive polyamideimide oligomers and reactive polyamideamic acid oligomers disclosed herein because they can all be made from the same at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one self-reactive monomer or end-capping agent. Therefore, the component description applicable to the reactive polyamideimide oligomers and reactive polyamideamic acid oligomers disclosed herein is also applicable to the reactive carboxylic acid ammonium salt, except that the aromatic acid chloride is not required. Therefore, the aromatic diamine can be at least one of 1,3-phenylenediamine, 4,4'diphenylamine oxide or 3,4'diphenylamine oxide, and the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent can be at least one of trimellitic anhydride, isophthalic anhydride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride. The unreacted functional groups involved in subsequent chain extension, branching and crosslinking reactions can be at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl or benzoxazine. Table 1 gives the chemical formula, chemical name and curing temperature range of these unreacted functional groups. The at least one crosslinkable monomer or crosslinkable end-capping agent can be two crosslinkable monomers or crosslinkable end-capping agents that are reactive at different temperature ranges. In some embodiments, the crosslinkable monomer or crosslinkable end-capping agent is at least one of 4-ethynyl phthalic anhydride, 4-methylethynyl phthalic anhydride, 4-phenylethynyl phthalic anhydride (PEPA) or 4,4'-(acetylene 1,2-diacyl) diphthalic anhydride.

[0125] The reactive carboxylic acid ammonium salt may also contain units derived from at least one non-crosslinking end-capping agent, wherein the non-crosslinking end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, but has no unreacted functional groups capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed. The non-crosslinking end-capping agent may be at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

[0126] Advantageously, the reactive carboxylic acid ammonium salt may have a melt complex viscosity of about 1 to about 100 Pa·s between about 80° C. and about 120° C., as determined by heating the melt at N 2 Oscillatory shear rheology was measured between parallel plates at a heating rate of 10 °C / min, a frequency of 2 rad / s, and a strain of 0.03%-1.0%. In this range, the melt complex viscosity is M n and the type and relative amounts of at least one diamine, at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, crosslinkable or non-crosslinkable monomer and end-capping agent present. Depending on the preparation method, the reactive carboxylic acid ammonium salt may also be melted at about 320°C.

[0127] The method for preparing a reactive ammonium carboxylate salt comprises:1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of at least one of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; and removing excess C 1-4 wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

[0128] As with reactive polyamide-imide oligomers and reactive polyamide-amic acid oligomers, reactive carboxylic acid ammonium salts need to be compounded with other materials. The method of compounding reactive polyamide-amic acid oligomers includes mixing reactive polyamide-amic acid oligomers with at least one other material at a temperature and time sufficient to melt but not crosslink reactive polyamide-amic acid oligomers. The material can be at least one polymer, filler or additive.

[0129] Like reactive polyamideimide oligomers and reactive polyamideamic acid oligomers, reactive carboxylic acid ammonium salts can be used to make various articles or parts with useful properties. Therefore, the method of making the article includes heating the reactive carboxylic acid ammonium salt at a temperature, pressure and time sufficient to prepare, shape and crosslink the reactive polyamideimide oligomer. The temperature and time sufficient to prepare, shape and crosslink the reactive polyamideamic acid oligomer are about 300°C to about 400°C, 0 to about 300 MPa, and about 10 to about 60 minutes.

[0130] For example, the manufacturing method can be fiber reinforced composite manufacturing, pultrusion, compression molding, injection molding or solution casting. Also disclosed is an article manufactured by the method. The manufacturing method and the article manufactured by the method are described below.

[0131] The manufacturing method may be a fiber reinforced composite material manufacturing. The active carboxylic acid ammonium salt may be in the form of a powder or a film. Thus, the fiber reinforced composite material manufacturing may include heating at least one layer of fiber fabric and at least one layer of active carboxylic acid ammonium salt as a powder or a film at a temperature, pressure and time sufficient to impregnate the fiber fabric with the active carboxylic acid ammonium salt and to prepare and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

[0132] The reactive ammonium carboxylate salt can also be dissolved in a polar solvent. Thus, the fiber reinforcement manufacturing method can include impregnating a fiber fabric with a solution of a reactive ammonium carboxylate salt dissolved in a polar solvent; removing the polar solvent under reduced pressure; and heating at a temperature, pressure, and time sufficient to polymerize and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material. For example, the fiber can be carbon fiber, glass fiber, cellulose (wood fiber / paper fiber, straw), polyamine (polyterephthalamide), polybenzoxazole (PBO) or polybenzimidazole (PBI).

[0133] Also disclosed is a fiber reinforced composite material, which is made of a reactive ammonium carboxylate salt by any of the above methods. For example, the composite material can be a multilayer carbon reinforced composite material. The multilayer reinforced composite material can have any number of layers, but in some embodiments, the number of layers is greater than or equal to 2 layers and less than or equal to 1000 layers.

[0134] The manufacturing method may be solution casting. The solution casting comprises: casting a reactive carboxylic acid ammonium salt solution dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive carboxylic acid ammonium salt film; and heating the reactive carboxylic acid ammonium salt film at a temperature, pressure, and time sufficient to prepare and crosslink the reactive polyamideimide oligomer to form a flexible film. A flexible film prepared by reactive carboxylic acid ammonium salt solution casting is also disclosed.

[0135] The manufacturing method may also be injection molding of the reactive ammonium carboxylate salt. Also disclosed is a product manufactured by injection molding of the reactive ammonium carboxylate salt. The manufacturing method may also be compression molding of the reactive ammonium carboxylate salt. The present invention also discloses a product manufactured by compression molding of the reactive ammonium carboxylate salt.

[0136] Reactive polyamideimide oligomers and reactive polyamide amic acid oligomers ("reactive oligomers"), methods of making reactive oligomers using reactive oligomers, and articles made from reactive oligomers have several advantageous properties. Currently available high molecular weight PAIs can have relatively high levels of amic acid groups in order to have sufficiently low complex viscosities to be melt processable. The presence of amic acid groups can make PAIs extremely hygroscopic. Therefore, pre-processing drying is also required. For example, Figure 1The manufacture and processing of currently available PAI of the illustrated construction involves imidization of polyamide amic acid profiles or injection molded parts, requiring a long thermal post-treatment to remove water generated from the conversion of amic acid groups to imide groups. Processed PAI parts are also exposed to a multi-day thermal treatment regimen after processing. The general curing schedule recommended by the manufacturer is: 375℉ (191℃) 1 day, 425℉ (218℃) 1 day, 475℉ (246℃) 1 day and 500℉ (260℃) 5 days, for a total of 8 days. In contrast, the curing of reactive polyamideimide oligomers at about 300 to about 450℃ can be completed in as little as about 1 to about 60 minutes. Advantageously, this reduction in thermal post-treatment time results in a significant reduction in manufacturing cycle time and cost.

[0137] With an M of about 1000 to about 10000 g / mol n The reactive polyamideimide oligomer advantageously exhibits a melt complex viscosity of about 1000 to about 100000 Pa.s at 360°C, particularly about 5000 to about 30000 Pa.s at 360°C. In contrast, currently available PAI is reported to have a melt complex viscosity of about 1000000 Pa.s at 2 rad / sec. The low melt complex viscosity of the fully imidized reactive polyamideimide oligomer relative to the currently available PAI is unexpected. In contrast to the low melt complex viscosity obtained, the alternating combination of rigid backbone phthalimide units and aromatic amide units that are expected to be strongly hydrogen-bonded as in polyaramids is expected to result in a high melting point and a high melt complex viscosity even for reactive polyamideimide oligomers. Advantageously, with a melt complex viscosity in the range of about 1000 to about 100,000 Pa·s at 360° C., conventional melt processing equipment can be used for melt processing and ready-to-use injection molded parts, films, fibers, and melt-processable high temperature adhesives can be made. In addition, compared to polyamide amic acid polymers, fully imidized reactive polyamideimide oligomers are less hygroscopic than polyamide amic acid polymers and are insoluble in polar solvents such as DMF, NMP, and DMAc, depending on the monomers and reactive and non-reactive end-capping agents used.

[0138] Advantageously, the thermal curing temperature range and the post-curing thermomechanical properties can be controlled by selecting the backbone monomer, the crosslinkable monomer, the crosslinkable end-capping agent, and the non-crosslinkable end-capping agent. In addition, improved thermomechanical properties are obtained using the reactive polyamideimide oligomers of the present invention. Referring to Example 1C below, which is M n The T of the film made of the reactive polyamideimide oligomer and cured at 370°C for 1 hour is 5000 g / mol, wherein both reactive end groups are phenylacetylene. g The T of currently available PAI films is 326°C.g High about 46 ° C. Also refer to Example 2 below, which is a 5000 g / mol M n Reactive polyamideimide oligomer with mixed reactive end groups (50 / 50 methylacetylene / phenylacetylene). T of films made from reactive polyamideimide oligomer and cured at 370°C for 1 hour g The toughness of the film is 94.3MJ / m 3 In comparison, the toughness of currently available PAI is only about 10 MJ / m 3 Therefore, the toughness of the PAI film made from this reactive polyamideimide oligomer is almost 10 times that of the PAI made from currently available PAI. g , breaking strength and breaking elongation are also improved.

[0139] Advantageously, the low melt complex viscosity of the reactive polyamideimide oligomers relative to high molecular weight polyamideimide polymers makes the reactive polyamideimide oligomers ideally suited for use in preparing fiber reinforced composites, such as glass, carbon and aramid fiber reinforced composites.

[0140] Solution-based prepreg, melt infusion and melt pultrusion methods can all be used. High molecular weight polyamide amic acid can be used to prepare fiber / resin prepregs and composite materials. However, it is difficult to obtain sufficient melt flow to melt and consolidate the polyamide amic acid prepreg into a composite board. In addition, during the imidization process of polyamide amic acid, it may be difficult to remove water from the composite board. This means that it is difficult to achieve a void of less than 2%, which is considered acceptable. Alternatively, the high molecular weight polyamide amic acid can be converted into a high molecular weight polyamide-imide in the prepreg stage, and the polyamide-imide prepreg can be consolidated into a composite material. The even higher melt complex viscosity of high molecular weight polyamide-imide makes it difficult to obtain sufficient melt flow under pressure to consolidate the prepreg into a composite board of acceptable quality. Therefore, the relatively low melt complex viscosity of reactive polyamide-imide oligomers provides advantages over both high molecular weight polyamide-imide and high molecular weight polyamide amic acid in the manufacture of fiber-reinforced composite materials.

[0141] The low melt complex viscosity of reactive polyamideimide oligomers compared to high molecular weight polyamideimide polymers also makes them ideally suited for 3D printing applications. Reactive polyamideimide oligomers can be used in filament, rod or powder form.

[0142] The present disclosure is further illustrated by the following aspects of the present disclosure, which are not intended to limit the claims.

[0143] Embodiments based on the current claims

[0144] Aspect 1. A reactive polyamideimide oligomer comprising units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least one crosslinkable monomer or crosslinkable end-capping agent; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of thermal chain extension and crosslinking after the reactive polyamideimide oligomer is formed; and wherein the number average molecular weight (M) of the reactive polyamideimide oligomer is n ) is calculated using the Carothers equation to be about 1000 to about 10000 g / mol.

[0145] Aspect 2. The reactive polyamideimide oligomer according to aspect 1, wherein the reactive polyamideimide oligomer is derived from a reactive polyamideamic acid oligomer intermediate by dehydration cyclization, and greater than 80% and less than or equal to 100% of the amic acid groups in the reactive polyamideamic acid intermediate are imidized.

[0146] Aspect 3. The reactive polyamideimide oligomer according to aspect 1, wherein the reactive polyamideimide oligomer is derived from a reactive polyamideamic acid oligomer intermediate by dehydration cyclization, and greater than or equal to 20% and less than or equal to 80% of the amic acid groups in the reactive polyamideamic acid intermediate are imidized.

[0147] Aspect 4. The reactive polyamideimide oligomer according to any one of aspects 1 to 3, wherein the crosslinkable monomer or crosslinkable end-capping agent has an unreacted functional group capable of thermal chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0148] Aspect 5. The reactive polyamideimide oligomer according to any one of aspects 1 to 4, wherein the at least one crosslinkable monomer or crosslinkable endcapping agent is at least one crosslinkable endcapping agent.

[0149] Aspect 6. The reactive polyamideimide oligomer according to any one of aspects 1 to 5, wherein the at least one aromatic diamine is two aromatic diamines.

[0150] Aspect 7. The reactive polyamideimide oligomer according to any one of aspects 1 to 6, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

[0151] Aspect 8. A reactive polyamideimide oligomer according to any one of Aspects 1 to 7, prepared by a method comprising: simultaneously stepwise polymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and at least one crosslinkable monomer or crosslinkable end-capping agent.

[0152] Aspect 9. The reactive polyamideimide oligomer according to any one of aspects 1 to 8, wherein the aromatic diamine is at least one of:

[0153]

[0154] Aspect 10. The reactive polyamideimide oligomer according to any one of aspects 1 to 9, wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, and 3,4'-oxydiphenylamine.

[0155] Aspect 11. The reactive polyamideimide oligomer according to any one of aspects 1 to 10, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of:

[0156]

[0157] Aspect 12. A reactive polyamideimide oligomer according to any one of aspects 1 to 11, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent is at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

[0158] Aspect 13. The reactive polyamideimide oligomer according to any one of aspects 1 to 12, wherein the unreacted functional group is at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl or benzoxazine.

[0159] Aspect 14. The reactive polyamideimide oligomer according to any one of aspects 1 to 13, wherein the crosslinkable monomer or crosslinkable end-capping agent is at least one of:

[0160]

[0161] Aspect 15. The reactive polyamideimide oligomer according to any one of aspects 1 to 14, wherein the crosslinkable monomer or crosslinkable end-capping agent is at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA) or 4,4'-(ethynyl-1,2-diyl)diphthalic anhydride.

[0162] Aspect 16. The reactive polyamideimide oligomer according to any one of aspects 1 to 15, comprising two cross-linkable monomers or cross-linkable end-capping agents having reactivity in different temperature ranges.

[0163] Aspect 17. A reactive polyamideimide oligomer according to any one of aspects 1 to 16, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof.

[0164] Aspect 18. The reactive polyamideimide oligomer according to aspect 17, wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

[0165] Aspect 19. The reactive polyamideimide oligomer according to any one of aspects 1 to 18, further comprising units derived from at least one of an aromatic triamine, an aromatic tricarboxylic acid, or an aromatic tricarboxylic acid chloride.

[0166] Aspect 20. The reactive polyamideimide oligomer according to any one of aspects 1 to 19, wherein the reactive polyamideimide oligomer has a melt complex viscosity at 360° C. of about 1000 to about 100000 Pa·s, wherein the melt complex viscosity is in N 2 The rheology was measured by oscillatory shear rheology between parallel plates at a heating rate of 10°C / min, a frequency of 2 rad / sec, and a strain of 0.03% to 1.0%.

[0167] Aspect 21. A reactive polyamideimide oligomer comprising units derived from:

[0168] At least one aromatic diamine selected from the group consisting of:

[0169]

[0170] A di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of the following:

[0171] as well as

[0172] At least one crosslinkable monomer or crosslinkable end-capping agent selected from the group consisting of:

[0173]

[0174]

[0175] Aspect 22. A reactive polyamideimide oligomer comprising units derived from: an aromatic diamine selected from at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine or 3,4'-oxydiphenylamine; a di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride; and a crosslinkable monomer or crosslinkable end-capping agent selected from at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA) or 4,4'-(ethynyl-1,2-diyl)diphthalic anhydride.

[0176] Aspect 23. A method for manufacturing a reactive polyamideimide oligomer according to any one of Aspects 1 to 22, the method comprising: copolymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one cross-linkable monomer or cross-linkable end-capping agent in the presence of a polar solvent to form a reactive polyamide amic acid oligomer; and heating the reactive polyamide amic acid oligomer at a sufficient temperature and time to prepare the reactive polyamideimide oligomer; wherein the cross-linkable monomer or cross-linkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamideimide oligomer is formed.

[0177] Aspect 24. The manufacturing method according to aspect 23, wherein the sufficient temperature and time to prepare the reactive polyamideimide oligomer is from about 140° C. to about 220° C. for about 1 minute to about 120 minutes.

[0178] Aspect 25. The production method according to aspect 23 or 24, wherein the polar solvent is at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane.

[0179] Aspect 26. The manufacturing method according to any one of aspects 23 to 25, further comprising removing the polar solvent from the polyamideamic acid oligomer before heating the reactive polyamideamic acid oligomer at a temperature and for a time sufficient to prepare the reactive polyamideimide oligomer.

[0180] Aspect 27. The manufacturing method according to aspect 26, wherein the sufficient temperature and time to prepare the reactive polyamideimide oligomer is from about 220° C. to about 300° C. for about 1 minute to about 120 minutes.

[0181] Aspect 28. The manufacturing method according to any one of aspects 23 to 27, wherein the method further comprises adding toluene to the reactive polyamide amic acid oligomer and azeotropically distilling toluene and water.

[0182] Aspect 29. The manufacturing method according to any one of aspects 23 to 27, wherein the method further comprises heating the reactive polyamide amic acid oligomer in the presence of acetic anhydride and a catalytic amount of a tertiary amine.

[0183] Aspect 30. The manufacturing method according to any one of aspects 23 to 27, wherein the method further comprises irradiating the reactive polyamide amic acid oligomer with microwaves.

[0184] Aspect 31. The production method according to any one of aspects 23 to 30, wherein the copolymerization is carried out in the presence of a phosphorylating agent and a catalytic amount of a salt.

[0185] Aspect 32. A method of making a reactive polyamideimide oligomer according to any one of aspects 1 to 22, the method comprising: reacting the oligomer in at least one of water or C at a sufficient temperature and time. 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of an alcohol to form at least one reactive carboxylic acid ammonium salt; optionally removing excess water or C 1-4 alcohol; and heating the reactive carboxylic acid ammonium salt at a sufficient temperature and time to form the reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0186] Aspect 33. The method of aspect 32, comprising reactively extruding the reactive carboxylic acid ammonium salt at a sufficient temperature and time to form the reactive polyamideimide oligomer.

[0187] Aspect 34. The method according to aspect 32, comprising dissolving the reactive carboxylic acid ammonium salt in a polar solvent and then heating at sufficient temperature, pressure and time to form the reactive polyamideimide oligomer.

[0188] Aspect 35. A method for making a reactive polyamideimide oligomer according to any one of Aspects 1 to 22, the method comprising reactively extruding at least one aromatic diamine or an activated derivative thereof, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least one crosslinkable monomer or crosslinkable endcapping agent at a sufficient temperature and time to prepare the reactive polyamideimide oligomer; wherein the crosslinkable monomer or crosslinkable endcapping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0189] Aspect 36. The manufacturing method according to Aspect 35, wherein the reactive extrusion is performed in the presence of a polar solvent, and the polar solvent is removed by distillation during the reactive extrusion.

[0190] Aspect 37. The manufacturing method according to aspect 35 or 36, wherein the reactive extrusion is carried out in the presence of an acidic catalyst.

[0191] Aspect 38. The manufacturing method according to aspect 37, wherein the acid catalyst is acetic acid, and the acetic acid is removed by distillation during the reactive extrusion.

[0192] Aspect 39. The manufacturing method according to any one of aspects 35 to 38, wherein the reactive extrusion is performed in the presence of acetic anhydride, and the acetic anhydride is removed by distillation during the reactive extrusion.

[0193] Aspect 40. The manufacturing method according to any one of aspects 35 to 39, wherein the reactive extrusion is performed in a melt extruder having a plurality of preset heating zones equipped with vents.

[0194] Aspect 41. A blend composition comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22 and a thermoplastic polymer.

[0195] Aspect 42. A powder coating composition comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0196] Aspect 43. A reactive adhesive composition comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0197] Aspect 44. A high temperature elastomeric composition prepared by heating the reactive polyamideimide oligomer according to any one of aspects 1 to 22 at a temperature and for a time sufficient to crosslink the reactive polyamideimide oligomer.

[0198] Aspect 45. A high temperature foam comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0199] Aspect 46. A method of compounding a reactive polyamideimide oligomer according to any one of aspects 1 to 22, comprising mixing the reactive polyamideimide oligomer with at least one other material at a sufficient temperature and time to melt but not crosslink the reactive polyamideimide oligomer.

[0200] Aspect 47. A method of making an article, the method comprising heating the reactive polyamideimide oligomer according to any one of aspects 1 to 22 at a sufficient temperature and for a sufficient time to shape and crosslink the reactive polyamideimide oligomer.

[0201] Aspect 48. The method of manufacturing according to aspect 47, wherein the sufficient temperature and time is about 300 to about 450° C. for about 1 to about 60 minutes.

[0202] Aspect 49. A manufacturing method according to aspect 47 or 48, wherein the method is additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging.

[0203] Aspect 50. An article manufactured by the method according to any one of aspects 47 to 49.

[0204] Aspect 51. An article comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0205] Aspect 52. The article according to aspect 51, wherein the reactive polyamideimide oligomer is cross-linked.

[0206] Aspect 53. The manufacturing method according to any one of aspects 47 to 49, wherein the method is a fiber-reinforced composite material manufacturing method.

[0207] Aspect 54. A method according to aspect 53, the method comprising heating at least one layer of fiber fabric and at least one layer of reactive polyamideimide oligomer as a powder or film at sufficient temperature, pressure and time to melt the reactive polyamideimide oligomer, impregnate the fiber fabric, and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

[0208] Aspect 55. A method according to aspect 53, comprising: impregnating at least one layer of fiber fabric with a solution of a reactive polyamideimide oligomer dissolved in a polar solvent; removing the polar solvent under reduced pressure; and heating at sufficient temperature, pressure and time to crosslink the reactive polyamideimide oligomer and form a fiber-reinforced composite material.

[0209] Aspect 56. A fiber-reinforced composite material produced by the method according to any one of aspects 53 to 55.

[0210] Aspect 57. A fiber-reinforced composite material comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0211] Aspect 58. The fiber-reinforced composite material according to aspect 57, wherein the reactive polyamideimide oligomer is cross-linked.

[0212] Aspect 59. The fiber-reinforced composite material according to aspect 57, wherein the composite material is a multi-layer carbon-reinforced composite material.

[0213] Aspect 60. The manufacturing method according to any one of aspects 47 to 49, wherein the method is pultrusion for manufacturing a unidirectional tape.

[0214] Aspect 61. A unidirectional tape prepared by the method according to aspect 60.

[0215] Aspect 62. A unidirectional tape comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0216] Aspect 63. The unidirectional tape according to Aspect 62, wherein the reactive polyamideimide oligomer is cross-linked.

[0217] Aspect 64. The manufacturing method according to any one of aspects 47 to 49, wherein the method is solution spinning or melt spinning of fibers.

[0218] Aspect 65. A fiber produced by the method according to Aspect 64.

[0219] Aspect 66. A fiber comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0220] Aspect 67. The fiber according to Aspect 66, wherein the reactive polyamideimide oligomer is cross-linked.

[0221] Aspect 68. The manufacturing method according to any one of aspects 47 to 49, wherein the method is additive manufacturing.

[0222] Aspect 69. A manufacturing method according to Aspect 68, wherein the method is fused filament manufacturing, the method comprising extruding the reactive polyamideimide oligomer in adjacent horizontal layers so that an interface exists between each polyamideimide oligomer layer, and exposing the layers to heat at a temperature and for a time sufficient to crosslink the reactive polyamideimide oligomer and form an article.

[0223] Aspect 70. The manufacturing method according to aspect 68, wherein the method is selective laser sintering, the method comprising selectively sintering and crosslinking particles of the reactive polyamideimide oligomer with a laser to form an article.

[0224] Aspect 71. The manufacturing method according to aspect 68, wherein the method is directed energy deposition (DED) or laser engineered net shaping (LENS).

[0225] Aspect 72. An article made by the method according to any one of aspects 68 to 71.

[0226] Aspect 73. An additively manufactured article comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0227] Aspect 74. The additively manufactured article according to aspect 73, wherein the reactive polyamideimide oligomer is cross-linked.

[0228] Aspect 75. A manufacturing method according to any one of Aspects 47 to 49, wherein the method is solution casting and comprises: casting a solution of a reactive polyamideimide oligomer dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive polyamideimide oligomer film; and heating the polyamideimide oligomer film at a temperature and for a time sufficient to crosslink the polyamideimide oligomers and form a flexible film.

[0229] Aspect 76. A flexible film manufactured by the solution casting method according to aspect 75.

[0230] Aspect 77. A flexible film comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0231] Aspect 78. The flexible film according to aspect 77, wherein the reactive polyamideimide oligomer is cross-linked.

[0232] Aspect 79. A flexible film according to any one of aspects 76 to 78, wherein the flexible film exhibits at least one of the following: 2 The glass transition temperature (Tg) is about 280 to about 310°C as measured by differential scanning calorimetry at a heating rate of 10°C / min under N 2The storage modulus (E') is about 2.2 to about 3.4 GPa as measured by dynamic mechanical thermal analysis at a heating rate of 10°C / min and an oscillation rate of 1 Hz; the Young's modulus is about 3.0 to about 3.8 GPa, the breaking strength is about 130 to about 160 MPa, or the breaking strain is about 10 to 80%, all measured at 25°C.

[0233] Aspect 80. The manufacturing method according to any one of aspects 47 to 49, wherein the method is injection molding.

[0234] Aspect 81. An injection molded article produced by the method according to aspect 80.

[0235] Aspect 82. An injection molded article comprising the reactive polyamideimide oligomer according to any one of aspects 1 to 22.

[0236] Aspect 83. The additively manufactured article according to aspect 82, wherein the reactive polyamideimide oligomer is cross-linked.

[0237] Aspect 84. A reactive polyamide amic acid oligomer comprising units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof; and at least one crosslinkable monomer or crosslinkable end-capping agent, wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamide amic acid oligomer is formed; and wherein the number average molecular weight (M) of the reactive polyamide amic acid oligomer is n ) is calculated using the Carothers equation to be about 1000 to about 10000 g / mol.

[0238] Aspect 85. The reactive polyamide amic acid oligomer according to aspect 84, wherein 0% to about 20% of the amic acid groups are imidized.

[0239] Aspect 86. The reactive polyamide amic acid oligomer according to aspect 84 or 85, wherein the crosslinkable monomer or crosslinkable endcapping agent has an unreacted functional group capable of thermal chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0240] Aspect 87. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 86, wherein the at least one crosslinkable monomer or crosslinkable endcapping agent is at least one crosslinkable endcapping agent.

[0241] Aspect 88. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 87, wherein the at least one aromatic diamine is two aromatic diamines.

[0242] Aspect 89. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 88, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

[0243] Aspect 90. A reactive polyamide amic acid oligomer according to any one of aspects 84 to 89, prepared by a process comprising simultaneously stepwise polymerization of the at least one aromatic diamine, the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and the at least one crosslinkable monomer or crosslinkable endcapping agent.

[0244] Aspect 91. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 90, wherein the aromatic diamine is at least one of:

[0245]

[0246] Aspect 92. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 91, wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine.

[0247] Aspect 93. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 92, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of:

[0248]

[0249] Aspect 94. The reactive polyamide amic acid oligomer according to any one of Aspects 84 to 93, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

[0250] Aspect 95. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 94, wherein the at least one unreacted functional group is at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl, or benzoxazine.

[0251] Aspect 96. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 95, wherein the crosslinkable monomer or crosslinkable end-capping agent is at least one of:

[0252]

[0253]

[0254] Aspect 97. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 96, wherein the crosslinkable monomer or crosslinkable end-capping agent is at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA) or 4,4'-(acetylene-1,2-diyl)diphthalic anhydride.

[0255] Aspect 98. The reactive polyamide amic acid oligomer according to any one of aspects 84 to 97, comprising two cross-linkable monomers or cross-linkable end-capping agents having reactivity in different temperature ranges.

[0256] Aspect 99. The reactive polyamide amic acid oligomer according to any one of Aspects 84 to 98, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof.

[0257] Aspect 100. The reactive polyamide amic acid oligomer according to aspect 99, wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride, or aniline.

[0258] Aspect 101. A reactive polyamide amic acid oligomer comprising units derived from:

[0259] At least one aromatic diamine selected from the group consisting of:

[0260]

[0261] A di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of the following:

[0262] and at least one crosslinkable monomer or crosslinkable end-capping agent selected from the group consisting of:

[0263]

[0264]

[0265] Aspect 102. A reactive polyamide amic acid oligomer comprising units derived from: an aromatic diamine selected from at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine; a di-, tri-, or tetra-functional aromatic carboxylic acid or its functional equivalent selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride, or biphenyltetracarboxylic dianhydride; and a crosslinkable monomer or crosslinkable end-capping agent selected from at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA), or 4,4'-(ethynyl-1,2-diyl)diphthalic anhydride.

[0266] Aspect 103. A method for manufacturing a reactive polyamide amic acid oligomer according to any one of Aspects 84 to 102, the method comprising: copolymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one cross-linkable monomer or cross-linkable end-capping agent in the presence of a polar solvent to form the reactive polyamide amic acid oligomer; wherein the cross-linkable monomer or cross-linkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent, and has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamide amic acid oligomer is formed.

[0267] Aspect 104. The manufacturing method according to aspect 103, wherein the polar solvent is at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane.

[0268] Aspect 105. The manufacturing method according to aspect 103 or 104, further comprising isolating the reactive polyamide amic acid oligomer from the polar solvent.

[0269] Aspect 106. A blend composition comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102 and a thermoplastic polymer.

[0270] Aspect 107. A powder coating composition comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0271] Aspect 108. A reactive adhesive composition comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0272] Aspect 109. A high temperature foam comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0273] Aspect 110. A method of compounding a reactive polyamide amic acid oligomer according to any one of aspects 84 to 102, comprising mixing the reactive polyamide amic acid oligomer with at least one other material at a temperature and for a time sufficient to imidize the reactive polyamide amic acid oligomer without crosslinking.

[0274] Aspect 111. A method of making an article, the method comprising heating the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102 at a sufficient temperature and for a sufficient time to imidize, shape, and crosslink the reactive polyamide amic acid oligomer.

[0275] Aspect 112. The manufacturing method according to aspect 111, wherein the sufficient temperature and time are about 300 to about 400° C. for about 10 to about 60 minutes.

[0276] Aspect 113. The manufacturing method according to aspect 110 or 111, wherein the method is additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, reaction injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting, solution casting or forging.

[0277] Aspect 114. An article manufactured by the method according to any one of aspects 111 to 113.

[0278] Aspect 115. An article comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0279] Aspect 116. The manufacturing method according to any one of aspects 111 to 113, wherein the method is a fiber-reinforced composite material manufacturing method.

[0280] Aspect 117. The method according to aspect 116 comprises heating at least one layer of fiber fabric and at least one layer of reactive polyamide amic acid oligomer into a powder or film at sufficient temperature, pressure and time to imidize the reactive polyamide amic acid oligomer, impregnate the fiber fabric, and crosslink to form a fiber-reinforced composite material.

[0281] Aspect 118. The method according to aspect 116, comprising: impregnating at least one layer of fiber fabric with a solution of reactive polyamide amic acid oligomer dissolved in a polar solvent; removing the polar solvent under reduced pressure, and heating at a temperature, pressure and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer to form a fiber reinforced composite material.

[0282] Aspect 119. A fiber-reinforced composite material produced by the method according to any one of aspects 116 to 118.

[0283] Aspect 120. A fiber-reinforced composite material comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0284] Aspect 121. The fiber-reinforced composite material according to aspect 120, wherein the composite material is a multi-layer carbon-reinforced composite material.

[0285] Aspect 122. The manufacturing method according to any one of aspects 111 to 113, wherein the method is pultrusion for manufacturing a unidirectional tape.

[0286] Aspect 123. A unidirectional tape prepared by the method according to aspect 122.

[0287] Aspect 124. A unidirectional tape comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0288] Aspect 125. The manufacturing method according to any one of aspects 111 to 113, wherein the method is solution spinning or melt spinning of fibers.

[0289] Aspect 126. A fiber produced by the method according to aspect 125.

[0290] Aspect 127. A fiber comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0291] Aspect 128. The manufacturing method according to any one of aspects 111 to 113, wherein the method is additive manufacturing.

[0292] Aspect 129. A manufacturing method according to Aspect 128, wherein the method is fused filament manufacturing, the method comprising extruding the reactive polyamide amic acid oligomer in adjacent horizontal layers so that there is an interface between each reactive polyamide amic acid oligomer layer, and exposing the layers to heat at a temperature and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer and form the article.

[0293] Aspect 130. The manufacturing method according to aspect 128, wherein the method is selective laser sintering, the method comprising selectively sintering, imidizing and crosslinking particles of the reactive polyamide amic acid oligomer with a laser to form an article.

[0294] Aspect 131. The manufacturing method according to aspect 128, wherein the method is directed energy deposition (DED) or laser engineered net shaping (LENS).

[0295] Aspect 132. An article made by the method according to any one of aspects 128 to 131.

[0296] Aspect 133. An additively manufactured article comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0297] Aspect 134. A manufacturing method according to any one of Aspects 111 to 113, wherein the method is solution casting and comprises: casting a solution of a reactive polyamide amic acid oligomer dissolved in a polar solvent onto a mold; removing the solvent to form a reactive polyamide amic acid oligomer film; and heating the reactive polyamide amic acid oligomer film at a temperature and for a time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer and form a flexible film.

[0298] Aspect 135. A flexible film manufactured by the solution casting method according to aspect 134.

[0299] Aspect 136. A flexible film comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0300] Aspect 137. The manufacturing method according to any one of aspects 111 to 113, wherein the method is injection molding.

[0301] Aspect 138. An injection molded article manufactured by the method according to aspect 137.

[0302] Aspect 139. An injection molded article comprising the reactive polyamide amic acid oligomer according to any one of aspects 84 to 102.

[0303] Aspect 140. The manufacturing method according to any one of aspects 111 to 113, wherein the method is blow molding.

[0304] Aspect 141. A reactive carboxylic acid ammonium salt formed by a method comprising: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; removing excess C 1-4 alcohol; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

[0305] Aspect 142. The reactive carboxylate ammonium salt according to aspect 141, wherein the crosslinkable monomer or crosslinkable capping agent has an unreacted functional group capable of thermal chain extension and crosslinking after the formation of the reactive carboxylate ammonium salt.

[0306] Aspect 143. The reactive carboxylate ammonium salt according to aspect 141 or 142, wherein the at least one crosslinkable monomer or crosslinkable capping agent is at least one crosslinkable capping agent.

[0307] Aspect 144. The reactive ammonium carboxylate salt according to any one of aspects 141 to 143, wherein the at least one aromatic diamine is two aromatic diamines.

[0308] Aspect 145. The reactive carboxylate ammonium salt according to any one of aspects 141 to 144, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

[0309] Aspect 146. The reactive carboxylate ammonium salt according to any one of aspects 141 to 145, wherein the aromatic diamine is at least one of:

[0310]

[0311] Aspect 147. The reactive ammonium carboxylate salt according to any one of aspects 141 to 146, wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4'-diphenylamine oxide, or 3,4'-diphenylamine oxide.

[0312] Aspect 148. The reactive carboxylate ammonium salt according to any one of aspects 141 to 147, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of:

[0313]

[0314] Aspect 149. The reactive carboxylic acid ammonium salt according to any one of aspects 141 to 148, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of trimellitic anhydride, isophthalic anhydride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

[0315] Aspect 150. The reactive ammonium carboxylate salt according to any one of aspects 141 to 149, wherein the unreacted functional group is at least one of acetylene, methylacetylene, phenylacetylene, ketoacetylene, propargyl ether, norbornene, maleimide, cyanate, phthalonitrile, benzocyclobutene, biphenyl, or benzoxazine.

[0316] Aspect 151. The reactive carboxylate ammonium salt according to any one of aspects 141 to 150, wherein the crosslinkable monomer or crosslinkable capping agent is at least one of:

[0317]

[0318] Aspect 152. The reactive carboxylic acid ammonium salt according to any one of aspects 141 to 151, wherein the crosslinkable monomer or crosslinkable capping agent is at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA), or 4,4′-(ethynyl-1,2-diyl)diphthalic anhydride.

[0319] Aspect 153. The reactive ammonium carboxylate salt according to any one of aspects 141 to 152, comprising two crosslinkable monomers or crosslinkable capping agents having reactivity at different temperature ranges.

[0320] Aspect 154. The reactive carboxylic acid ammonium salt according to any one of aspects 141 to 153, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof.

[0321] Aspect 155. The reactive carboxylic acid ammonium salt according to aspect 154, wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

[0322] Aspect 156. The reactive ammonium carboxylate salt according to any one of aspects 141 to 155, wherein the reactive ammonium carboxylate salt has a melt complex viscosity of about 1 to about 100 Pa·s at about 80° C. to about 120° C., the viscosity being in N 2 The strains were measured by oscillatory shear rheology between parallel plates at a heating rate of 10°C / min, a frequency of 2 rad / sec, and a strain range of 0.03% to 1.0%.

[0323] Aspect 157. A reactive carboxylic acid ammonium salt comprising units derived from:

[0324] At least one aromatic diamine selected from the group consisting of:

[0325]

[0326] A di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of the following:

[0327] and

[0328] At least one crosslinkable monomer or crosslinkable end-capping agent selected from the group consisting of:

[0329]

[0330]

[0331] Aspect 158. A reactive carboxylic acid ammonium salt comprising units derived from: an aromatic diamine selected from at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine; a di-, tri-, or tetra-functional aromatic carboxylic acid or its functional equivalent selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride, or biphenyltetracarboxylic dianhydride; and a crosslinkable monomer or crosslinkable end-capping agent selected from at least one of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, 4-phenylethynylphthalic anhydride (PEPA), or 4,4'-(ethynyl-1,2-diacyl)phthalic anhydride.

[0332] Aspect 159. A method for producing a reactive ammonium carboxylate salt, the method comprising: 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-carboxylic acid or its functional equivalent, and at least one crosslinkable monomer or crosslinkable endcapping agent in the presence of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; removing excess C 1-4 alcohol; wherein the crosslinkable monomer or crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

[0333] Aspect 160. A method of compounding the reactive ammonium carboxylate salt of any of Aspects 141 to 158, comprising mixing the reactive ammonium carboxylate salt with at least one other material at a temperature, pressure, and time sufficient to produce but not crosslink a reactive polyamideimide oligomer.

[0334] Aspect 161. A method of making an article, the method comprising heating the reactive carboxylate ammonium salt according to any one of aspects 141 to 158 at a temperature, pressure, and time sufficient to prepare, shape, and crosslink the reactive polyamideimide oligomer.

[0335] Aspect 162. The manufacturing method according to aspect 161, wherein the sufficient temperature, pressure and time are about 300° C. to about 400° C., 0 to about 300 MPa, and about 10 to about 60 minutes.

[0336] Aspect 163. The manufacturing method according to aspect 161 or 162, wherein the method is fiber reinforced composite manufacturing, pultrusion, compression molding, injection molding or solution casting.

[0337] Aspect 164. An article manufactured by the method according to any one of aspects 161 to 163.

[0338] Aspect 165. The manufacturing method according to any one of aspects 161 to 163, wherein the method is fiber-reinforced composite material manufacturing.

[0339] Aspect 166. The method according to aspect 165, comprising heating at least one layer of fiber fabric and at least one layer of reactive ammonium carboxylate salt into a powder or film at a temperature, pressure and time sufficient to allow the reactive ammonium carboxylate salt to impregnate the fiber fabric and prepare and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

[0340] Aspect 167. The method according to aspect 165, comprising: impregnating at least one layer of fiber fabric with a solution of a reactive ammonium carboxylate salt dissolved in a polar solvent; removing the polar solvent under reduced pressure; and heating at a temperature, pressure, and time sufficient to polymerize and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

[0341] Aspect 168. A fiber-reinforced composite material produced by the method of any one of aspects 165 to 167.

[0342] Aspect 169. The fiber-reinforced composite material according to aspect 168, wherein the composite material is a multi-layer carbon-reinforced composite material.

[0343] Aspect 170. A manufacturing method according to any one of Aspects 161 to 163, wherein the method is solution casting and comprises: casting a solution of a reactive ammonium carboxylate salt dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive ammonium carboxylate salt film; and heating the reactive ammonium carboxylate salt film at a temperature, pressure and time sufficient to prepare and crosslink the reactive polyamideimide oligomer to form a flexible film.

[0344] Aspect 171. A flexible film manufactured by the solution casting method of Aspect 170.

[0345] Aspect 172. The manufacturing method according to any one of aspects 161 to 163, wherein the method is injection molding.

[0346] Aspect 173. The manufacturing method according to any one of aspects 161 to 163, wherein the method is blow molding.

[0347] Example

[0348] Materials and methods

[0349] Abbreviations for materials used or referred to herein are defined in Table 2. For those materials used in the Examples, sources are provided. Keywords for other abbreviations used herein are provided in Table 3.

[0350] Table 2. Materials

[0351]

[0352]

[0353] Table 3. Other abbreviations

[0354]

[0355]

[0356] Rheology. In N 2 Melt complex viscosity was measured by oscillatory shear rheology at a heating rate of 10°C / min, a frequency of 2 rad / sec, and a strain of 0.03% to 1.0%. A 13-mm diameter sample was centered between 25-mm diameter parallel plates for measurement.

[0357] Thermogravimetric analysis (TGA). To determine T d，5％重量损失 :TA Instruments TGA 5500, Pt disk, 10℃ / min, N 2 , 10mg sample.

[0358] Differential scanning calorimetry (DSC). For determination of T g :TA Instruments DSC2500, Tzero pan with sealed cover, 10℃ / min, N 2 , about 7 mg sample. In this method, T g Determined by the inflection point.

[0359] Dynamic Mechanical Thermal Analysis (DMTA). TA Instruments RSA G2 in tension mode, 2°C / min from 25°C to 400°C, N 2 atmosphere, sample size = 0.030 mm × 2 mm × 10 mm. In this method, T g Determined by the maximum value of the loss modulus peak.

[0360] Stress and strain measurements. TA Instruments RSA G2 (32N load cell), strain rate 1 mm / min, sample dimensions = about 0.030 mm x about 2 mm x 10 mm. Young's modulus was determined by linear fit of the stress-strain curve between the elastic region; 0.1 and 0.3% strain.

[0361] Gel permeation chromatography (GPC). The Shimadzu Prominence ultrafast liquid chromatography (UFLC) system was equipped with an LC20AD pump, a SIL-20A HT autosampler, a CTO-20A column oven at 60 °C, and a RID-20A refractive index detector. For the measurements, the chromatographic column used was SHODEX TMLF-804. The eluent used for the measurement was 0.05M LiBr and 0.05M MH 3 PO 4 of NMP at a constant flow rate of 0.5 mL / min. TM Polystyrene standards were used for comparison to obtain relative molecular weights.

[0362] Example 1

[0363] The preparation of reactive polyamideimide oligomers is illustrated in Scheme 5 below. The molecular weight of the oligomer affects the thermal, (thermo)mechanical and melt properties of the reactive polyamideimide oligomers. In this example, a phenylethynyl end-capping agent (PEPA) was used to prepare M n The reactive polyamideimide oligomers with M values ​​of 5000 g / mol (Examples 1B-1E), 3000 g / mol (Examples 1F-1G) and 8000 g / mol (Examples 1H-1I) were prepared. The Carothers equation (Eq. 2) was used to calculate the reaction conditions for preparing the oligomers with the desired M values. n The amount of monomer required to prepare the reactive polyamide-imide oligomer. n When more than one diamine monomer is used, the relative molar amounts of the diamine monomers will affect the rigidity of the oligomeric backbone. Therefore, the thermal, (thermo)mechanical and melt properties of the reactive polyamideimide oligomer can be changed by changing the ratio of the diamine monomers. n The molar ratio of the two diamines is 0.72:0.28, and the backbone is composed of 4,4'-ODA and 1,3-PD. Changing the molar ratio of the two diamines will result in changes in the properties of the oligomers. The molar ratio of 4,4'-ODA to 1,3-PD in Examples 1A-1I is 0.72:0.28, in Examples 1J-1K it is 0.62:0.32, and in Examples 1L-1M it is 0.813:0.197.

[0364]

[0365] Scheme 5. Synthesis of reactive polyamideimide oligomers with phenylethynyl reactive end groups.

[0366] Example 1A - Reactive polyamide amic acid oligomer solution, M n =5000g / mol

[0367] In a 150mL 2-necked round bottom flask equipped with a stirring rod and a nitrogen inlet tube, 1,3-phenylenediamine (6.38mmol, 0.69g), 4,4'-oxydiphenylamine (16.33mmol, 3.27g) and 37g NMP were charged. The mixture was stirred until a uniform solution was obtained. The solution was cooled to 0°C. Trimellitic anhydride chloride (21.28mmol, 4.48g) and 4-(phenylethynyl)phthalic anhydride (2.9mmol, 0.72g) were added all at once. The reaction mixture was stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16h) to provide a solution of reactive polyamide amic acid oligomer in NMP.

[0368] Example 1B - Reactive polyamideimide oligomer film, M n =5000g / mol

[0369] This is an example of preparing a free-standing reactive polyamideimide oligomer film without curing the phenylethynyl end groups. The reactive polyamide amic acid oligomer solution (10 mL) prepared in Example 1A was cast onto a glass plate and dried under vacuum at 60°C. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 h, 200°C for 1 h and 300°C for 1 h to obtain a reactive polyamideimide oligomer with unreacted phenylethynyl end groups. The film was brittle and difficult to handle, which is a direct consequence of the low molecular weight. g At 248 °C, differential scanning calorimetry (N 2 , 10℃ / min) measurement.

[0370] Example 1C - Cured polyamideimide oligomer film, M n =5000g / mol

[0371] This is an example of preparing a flexible, free-standing film with cured phenylethynyl end groups. A reactive polyamide amic acid oligomer solution (10 mL) as prepared in Example 1A was poured onto a glass plate and dried under vacuum at 60°C. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 h, 200°C for 1 h, and 300°C for 1 h to obtain a reactive polyamideimide oligomer with unreacted phenylethynyl end groups. The temperature was increased to 370°C and the film was kept at this temperature for 1 hour. After the film was cooled to 25°C, a flexible and tough film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 483°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g is 301℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 3.2GPa at 33℃ and 0.81GPa at 300℃, Tg The stress-strain experiment (25°C) showed that the film had a Young's modulus of 3.4 GPa, a fracture strength of 134 MPa, and a fracture strain of 17%. The film properties exceeded expectations for high molecular weight polymer films.

[0372] Example 1D - Isolated reactive polyamideimide oligomer powder, M n =5000g / mol

[0373] The imidized reactive polyamide-imide oligomer powder is obtained by precipitating the solution of the reactive polyamide-amic acid of Example 1A in NMP in MeOH. The polyamide-amic acid is precipitated by pouring 50mL of the polyamide-amic acid solution of Example 1A into 200mL of MeOH in a Warring blender and mixing for 1-3min. The precipitate is collected by filtration on a Buchner funnel and washed with another 200mL of MeOH. The washed polyamide-amic acid powder is dried in an oven at 60°C under vacuum for 2 hours. The temperature is gradually raised to 100°C for 1h, 200°C for 1h and 260°C for 1h to dehydrate the reactive polyamide-amic acid oligomer and obtain a reactive polyamide-imide oligomer powder with unreacted phenylethynyl end groups. Parallel plate rheology (N 2 ,10℃ / min) shows a melt complex viscosity of 19000Pa·s at 361℃.

[0374] Example 1E - Cured polyamideimide oligomer film, M n =5000g / mol

[0375] This is another example of preparing a flexible, free-standing film with cured phenylethynyl end groups. The reactive polyamide amic acid oligomer solution of Example 1A was imidized as follows. Anhydrous toluene was added to a reaction flask. The water formed during the cyclodehydration (amic acid to imide) was removed by azeotropic distillation. After 2 hours, the reactive polyamide amic acid oligomer was 98% imidized and the remaining toluene was removed by distillation. A solution (10 mL) of the resulting reactive polyamide imide oligomer in NMP (30 wt.% solid) was poured onto a glass plate and dried under vacuum at 60°C. After cooling to room temperature, the temperature was gradually raised to 40°C for 2h, 60°C for 2h, 100°C, 200°C, 300°C for 30min and 370°C for 1h. After the film was cooled to 25°C, a flexible and tough film was obtained. Differential Scanning Calorimetry (N 2 , 10℃ / min) shows T g It is 326°C, which is about 46°C higher than the Tg (280°C) of the currently available PAI film.

[0376] Example 1F, Cured Polyamide-Imide Oligomer Film, M n =3000g / mol

[0377] Preparation of M using 4-phenylethynylphthalic anhydride as a capping agent n =3000g / mol reactive polyamideimide oligomer. A 150mL 2-neck round-bottom flask equipped with a stirring rod and a nitrogen inlet tube was charged with 1,3-phenylenediamine (22.84mmol, 2.47g), 4,4'-oxydiphenylamine (62.07mmol, 12.43g) and 82g NMP. The mixture was stirred until a uniform solution was obtained. The solution was cooled to 0°C. Trimellitic anhydride chloride (76.08mmol, 16.02g) and 4-(phenylethynyl)phthalic anhydride (17.64mmol, 4.38g) were added all at once. The reaction mixture was stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16h), providing a solution of reactive polyamide amic acid oligomer in NMP. The reactive polyamide amic acid oligomer solution (10 mL) was poured onto a glass plate and dried under vacuum at 60°C. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 h, 200°C for 1 h and 300°C for 1 h to obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was increased to 370°C and the film was kept at this temperature for 1 hour. After the film was cooled to 25°C, a flexible film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 500°C. Differential scanning calorimetry (N 2 , 10℃ / min) showed that Tg was 291℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 1.71GPa at 35℃ and 0.25GPa at 300℃, T g The stress-strain test (25°C) shows that the film has a Young's modulus of 3.0 GPa, a fracture strength of 110 MPa, and a fracture strain of 16.4%.

[0378] Example 1G - Isolated reactive polyamideimide oligomer powder, M n =3000g / mol

[0379] The imidized reactive polyamide-imide oligomer powder is obtained by precipitating the solution of the reactive polyamide-amic acid of Example 1D in NMP in MeOH. The polyamide-amic acid is precipitated by pouring 50mL of the polyamide-amic acid solution of Example 1D into 200mL of MeOH in a Warring blender and mixing for 1-3min. The precipitate is collected by filtration on a Buchner funnel and washed with another 200mL of MeOH. The washed polyamide-amic acid powder is dried in an oven at 60°C under vacuum for 2 hours. The temperature is gradually raised to 100°C for 1h, 200°C for 1h and 260°C for 1h to dehydrate the reactive polyamide-amic acid oligomer to obtain a reactive polyamide-imide oligomer powder with unreacted phenylethynyl end groups. Parallel plate rheology (N 2 ,10℃ / min) shows a melt complex viscosity of 5450Pa·s at 361℃.

[0380] Example 1H - Cured polyamideimide oligomer film, M n =8000g / mol

[0381] Preparation of reactive polyamideimide oligomers having 4-phenylethynylphthalic anhydride reactive end groups, M n =8000g / mol. A 150mL 2-neck round-bottom flask equipped with a stirring rod and a nitrogen inlet tube was charged with 1,3-phenylenediamine (22.84mmol, 2.47g), 4,4'-oxydiphenylamine (56.43mmol, 11.30g) and 73g NMP. The mixture was stirred until a uniform solution was obtained. The solution was cooled to 0°C. Trimellitic anhydride chloride (76.08mmol, 16.02g) and 4-(phenylethynyl)phthalic anhydride (6.04mmol, 1.5g) were added all at once. The reaction mixture was stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16h) to provide a solution of reactive polyamide amic acid oligomers in NMP. The reactive polyamide amic acid oligomer solution (10 mL) was cast onto a glass plate and dried at 40°C for 2 hours and at 60°C for 2 hours under vacuum. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was increased to 370°C and the film was kept at this temperature for 1 hour. After cooling to 25°C, a flexible film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 490°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g is 287℃. Dynamic mechanical thermal analysis (N 2, 10℃ / min, 1Hz) shows that the storage modulus (E') is 3.0GPa at 35℃ and 0.75GPa at 300℃, T g The stress-strain experiment (25°C) showed that the Young's modulus of the film was 3.1 GPa, the fracture strength was 139 MPa, and the fracture strain was 57.4%.

[0382] Example II - Isolated reactive polyamideimide oligomer powder, M n =8000g / mol

[0383] The imidized reactive polyamide-imide oligomer powder was obtained by precipitating the reactive polyamide-amic acid solution of Example 1F in NMP in MeOH. The polyamide-amic acid was precipitated by pouring 50 mL of the polyamide-amic acid solution into 200 mL of MeOH in a Warring blender and mixing for 1-3 min. The precipitate was collected by filtration on a Buchner funnel and washed with an additional 200 mL of MeOH. The washed polyamide-amic acid powder was vacuum dried at 60° C. in a tam oven for 2 hours. The temperature was gradually increased to 100° C. for 1 h, 200° C. for 1 h, and 260° C. for 1 h to dehydrate the reactive polyamide-amic acid oligomer to obtain a reactive polyamide-imide oligomer powder with unreacted phenylethynyl end groups. Parallel plate rheology (N 2 ,10℃ / min) shows a melt complex viscosity of 49902Pa·s at 333℃.

[0384] Example 1J - Cured oligomeric polyamideimide oligomer film, 4,4'-ODA:1,3-PD ratio = 0.62: 0.32,M n =5000g / mol

[0385] In this example, the molar ratio of two diamines; 4,4'-ODA and 1,3-PD is 0.62:0.32. A 150mL 2-neck round-bottom flask equipped with a stirring bar and a nitrogen inlet tube is charged with 1,3-phenylenediamine (37.54mmol, 4.06g), 4,4'-oxydiphenylamine (62.52mmol, 12.52g) and 92g NMP. The mixture is stirred until a uniform solution is obtained. The solution is cooled to 0°C. Trimellitic anhydride chloride (93.89mmol, 19.77g) and 4-(phenylethynyl)phthalic anhydride (12.41mmol, 3.08g) are added all at once. This reaction mixture is stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath is removed and the reaction mixture is stirred and warmed to 25°C overnight (about 16 hours) to provide a solution of reactive polyamide amic acid oligomers in NMP. The reactive polyamide amic acid oligomer solution (10 mL) was cast onto a glass plate and dried at 40°C for 2 hours and at 60°C for 2 hours under vacuum. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was increased to 370°C and the film was kept at this temperature for 1 hour. After cooling to 25°C, a flexible film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 478°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g is 283℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 2.0GPa at 35℃ and 0.24GPa at 300℃, T g The stress-strain test (25°C) showed that the Young's modulus of the film was 2.5 GPa, the breaking strength was 82.5 MPa, and the breaking strain was 10.1%.

[0386] Example 1K - Isolated reactive polyamideimide oligomer powder, 4,4'-ODA:1,3-PD ratio = 0.62:0.32,M n =5000g / mol

[0387] The imidized reactive polyamide-imide oligomer powder is obtained by precipitating the solution of the reactive polyamide-amic acid oligomer of Example 1I in NMP in MeOH. The reactive polyamide-amic acid oligomer is precipitated by pouring 50mL of the reactive polyamide-amic acid oligomer solution into 200mL of MeOH in a Waring blender and mixing for 1-3 minutes. The precipitate is collected by filtering on a Buchner funnel and washed with another 200mL of MeOH. The washed reactive polyamide-amic acid oligomer powder is dried in an oven at 60°C under vacuum for 2 hours. Gradually warming up to 100°C for 1h, 200°C for 1h and 260°C for 1h, the reactive polyamide-amic acid oligomer is dehydrated, and a reactive polyamide-imide oligomer powder with unreacted phenylethynyl end groups is obtained. Parallel plate rheology (N 2 , 10°C / min) showed that the melt complex viscosity at 370°C was 40339 Pa·s.

[0388] Example 1L - Cured oligomeric polyamideimide oligomer film, 4,4'-ODA:1,3-PD ratio = 0.813: 0.197,M n =5000g / mol

[0389] In this example, the molar ratio of two diamines; 4,4'-ODA and 1,3-PD is 0.813:0.187. A 150mL 2-necked round-bottom flask equipped with a stirring rod and a nitrogen inlet tube was charged with 1,3-phenylenediamine (18.77mmol, 2.03g), 4,4'-oxydiphenylamine (81.70mmol, 16.36g) and 96g NMP. The mixture was stirred until a uniform solution was obtained. The solution was cooled to 0°C. Trimellitic anhydride chloride (93.89mmol, 19.77g) and 4-(phenylethynyl)phthalic anhydride (12.41mmol, 3.08g) were added all at once. The reaction mixture was stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16h) to provide a solution of reactive polyamide amic acid oligomers in NMP. The reactive polyamide amic acid oligomer solution (10 mL) was cast onto a glass plate and dried at 40°C for 2 hours and at 60°C for 2 hours under vacuum. The reactive polyamide amic acid oligomer was dehydrated by gradually increasing the temperature to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was increased to 370°C and the film was kept at this temperature for 1 hour. After cooling to 25°C, a flexible film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 496°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T gis 308℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 2.5GPa at 35℃ and 1.0GPa at 300℃, T g The stress-strain experiment (25°C) showed that the Young's modulus of the film was 3.7 GPa, the fracture strength was 132 MPa, and the fracture strain was 12.6%.

[0390] Example 1M - Isolated reactive polyamideimide oligomer powder, 4,4'-ODA:1,3-PD ratio = 0.813:0.197,M n =5000g / mol

[0391] The reactive polyamide-imide oligomer powder of imidization is obtained by precipitating the solution of reactive polyamide-amic acid oligomer in NMP in MeOH. By pouring 50mL reactive polyamide-amic acid oligomer solution into 200mL MeOH in Warring blender and mixing for 1-3min, the reactive polyamide-amic acid oligomer is precipitated. The mixture is washed in Warring blender for 1-3 minutes. The precipitate is collected by filtering on Buchner funnel and washed with another 200mL MeOH. The washed reactive polyamide-amic acid oligomer powder is dried in an oven at 60°C under vacuum for 2 hours. The temperature is gradually increased to 100°C for 1h, 200°C for 1h and 260°C for 1h, and the reactive polyamide-amic acid oligomer is dehydrated to obtain the reactive polyamide-imide oligomer powder with unreacted phenylethynyl end groups. The parallel plate rheology (N 2 , 10℃ / min) showed that the melt complex viscosity at 359℃ was 49502Pa·s.

[0392] Example 2

[0393] Two different capping agents were used to make M n A reactive polyamideimide (PAI) oligomer of 5000 g / mol is shown below in Scheme 6. The two different end-capping agents are 4-(phenylethynyl)phthalic anhydride and 4-(methylethynyl)phthalic anhydride.

[0394]

[0395] Scheme 6. Synthesis of M with two different reactive end groups n =5000 g / mol fully aromatic reactive polyamideimide oligomer. 50 / 50 4-(phenylethynyl)phthalic anhydride / 4-(methylethynyl)phthalic anhydride.

[0396] 1,3-phenylenediamine (6.38mmol, 0.69g), 4,4'-oxydiphenylamine (16.33mmol, 3.27g) and 36g NMP were placed in a 150mL 2-neck round-bottom flask equipped with a stirring rod and a nitrogen inlet tube. The mixture was stirred until a uniform solution was obtained. The solution was cooled to 0°C. Trimellitic anhydride chloride (21.28mmol, 4.48g), 4-(phenylethynyl)phthalic anhydride (1.45mmol, 0.36g) and 4-(methylethynyl)phthalic anhydride (1.45mmol, 0.27g) were added all at once. The reaction mixture was stirred at 0°C for 1 to 2 hours under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16 hours). The prepared reactive polyamide amic acid oligomer solution (10mL) was poured onto a glass plate and dried at 60°C under vacuum. The temperature was gradually raised to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to dehydrate the reactive polyamide amic acid oligomer and obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was raised to 370°C and the film was kept at this temperature for 1 hour. After the film was cooled to 25°C, a flexible and tough film was obtained.

[0397] Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 466°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g is 298℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 2.6 GPa at 33℃ and 0.64 GPa at 300℃, T g Parallel plate rheology (N 2 ,10℃ / min) showed a viscosity of 98560Pa·s at 301℃. Stress-strain experiments at 25℃ showed that the film had a Young's modulus of 3.6GPa, a breaking strength of 155MPa, an elongation at break of 75%, and a toughness of 94.3MJ / m 3 In contrast, a review of the existing literature shows that currently available PAIs have only about 10 MJ / m 3 The PAI films made from reactive polyamideimide oligomers can have toughness of 100 MPa, strength at break of 140 MPa, and elongation at break of 10 to 15%. Thus, the toughness of PAI films made from reactive polyamideimide oligomers can be almost 10 times higher than the toughness of currently available PAI, the elongation at break can be about 5 times higher, and the strength at break can be about 10% higher. Typically, crosslinking of polymers results in a decrease in elongation at break. Surprisingly, when the reactive polyamideimide oligomers are crosslinked, both the strength at break and the elongation at break increase, resulting in a substantial increase in toughness.

[0398] Example 3

[0399] Another reactive polyamideimide oligomer is made as shown in Scheme 7 below. TMACl is expensive, so it is desirable to minimize its use in the manufacture of reactive polyamideimide oligomers. TMACl has an acyl chloride group and a carboxylic anhydride group. Instead of using one equivalent of TMACl, 1 / 2 equivalent of pyromellitic dianhydride (PMDA) and 1 / 2 equivalent of isophthalic acid chloride (IPC) were used. Preparation of M with 4-(phenylethynyl)phthalic anhydride reactive end groups n It is a reactive oligomer of 5000 g / mol.

[0400]

[0401] Scheme 7. M with 4-(phenylethynyl)phthalic anhydride reactive end group n = Synthesis of 5000 g / mol fully aromatic reactive polyamideimide oligomer. The trimellitic anhydride chloride of Example 2 was replaced by pyromellitic dianhydride and isophthaloyl chloride.

[0402] In a 150mL 2-neck round bottom flask equipped with a stirring rod and a nitrogen inlet tube, pyromellitic anhydride (10.64mmol, 2.32g), isophthaloyl chloride (10.64mmol, 2.16g), 4-(phenylethynyl)phthalic anhydride (2.9mmol, 0.72g) and 37g NMP were loaded. The suspension was stirred for 15min and cooled to 0°C. Diamine, 1,3-phenylenediamine (6.38mmol, 0.69g) and 4,4'-oxydiphenylamine (16.33mmol, 3.27g) were all added at once. The reaction mixture was stirred at 0°C for 1 hour under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16 hours). The prepared reactive polyamide amic acid oligomer solution (10mL) was poured onto a glass plate and dried at 60°C under vacuum. The temperature was gradually raised to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to dehydrate the reactive polyamide amic acid oligomer and obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was raised to 370°C and the film was kept at this temperature for 1 hour. After the film was cooled to 25°C, a flexible and tough film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 476°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g is 315℃. Dynamic mechanical thermal analysis (N 2, 10℃ / min, 1Hz) shows that the storage modulus (E') is 2.8GPa at 33℃ and 0.93GPa at 300℃, T g The stress-strain experiment at 25°C showed that the Young's modulus of the film was 3.2 GPa, the breaking strength was 121 MPa, and the breaking elongation was 25%.

[0403] Example 4

[0404] Another reactive polyamideimide oligomer was prepared as shown below in Scheme 8. A cross-linkable dianhydride monomer (4,4'-(ethynyl-1,2-diyl) diphthalic dianhydride or EBPA) was incorporated into the reactive oligomer backbone. n ) is limited to 5000 g / mol, using phthalic anhydride (non-reactive) as the end-capping agent.

[0405]

[0406] Scheme 8. Synthesis of M n =5000 g / mol fully aromatic reactive polyamideimide oligomer with crosslinkable acetylene-based dianhydride monomer (4,4'-(acetylene-1,2-diyl) diphthalic dianhydride or EBPA) in the backbone. The molecular weight (M) was increased by using a non-reactive phthalic anhydride end-capping agent. n ) is limited to 5000 g / mol.

[0407] 4,4'-oxydiphthalic anhydride (ODPA) (7.98mmol, 2.48g), isophthaloyl chloride (10.64mmol, 2.16g), EBPA (2.66mmol, 0.85g), phthalic anhydride (2.9mmol, 0.43g) and 42g NMP were loaded into a 150mL 2-neck round-bottom flask equipped with a stirring rod and a nitrogen inlet tube. The suspension was stirred for 15min and cooled to 0°C. Diamine 4,4'-oxydiphenylamine (22.71mmol, 4.55g) was added all at once. The reaction mixture was stirred at 0°C for 1 hour under a nitrogen atmosphere, and then the ice bath was removed, and the reaction mixture was stirred and warmed to 25°C overnight (about 16 hours). The prepared reactive polyamide amic acid oligomer solution (10mL) was cast onto a glass plate and dried at 60°C under vacuum to form a film. The temperature was gradually raised to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to dehydrate the reactive polyamide amic acid oligomer and obtain a reactive polyamide imide oligomer with unreacted phenylethynyl end groups. The temperature was raised to 370°C and the film was kept at this temperature for 1 hour. After cooling the film to 25°C, a flexible and tough film was obtained. After cooling to 25°C, a flexible and tough film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 463°C. Differential scanning calorimetry (N 2 , 10℃ / min) shows T g It is 268℃.

[0408] Another thin film was formed in the same manner, except that the reactive polyamideimide oligomer film was cured at 400°C instead of at 400°C for 1 hour. 2 , 10°C / min) showed a weight loss of 5% at 459°C. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 2.0GPa at 33℃ and 0.16GPa at 300℃, T g The stress-strain experiment at 25°C showed that the Young's modulus of the film was 2.1 GPa, the breaking strength was 56 MPa, and the breaking elongation was 3%.

[0409] Example 5

[0410] Another reactive polyamideimide oligomer was prepared as shown below in Scheme 9. A cross-linkable dianhydride monomer (4,4'-(ethynyl-1,2-diyl) diphthalic dianhydride or EBPA) was incorporated into the reactive oligomer backbone. n ) was limited to 5000 g / mol, and 4-(phenylethynyl)phthalic anhydride reactive end-capping agent was used.

[0411]

[0412] Scheme 9. Synthesis of M n =5000 g / mol fully aromatic reactive polyamideimide oligomer with crosslinkable acetylene-based dianhydride monomer (4,4'-(ethynyl-1,2-diyl) diphthalic dianhydride or EBPA) in the backbone. The molecular weight (M) was increased to 100 g / mol using a reactive 4-(phenylethynyl)phthalic anhydride end-capping agent. n ) is limited to 5000 g / mol.

[0413] A 150 mL 2-necked round bottom flask equipped with a stirring bar and a nitrogen inlet was charged with 4,4'-oxydiphthalic anhydride (ODPA) (7.98 mmol, 2.48 g), isophthaloyl chloride (10.64 mmol, 2.16 g), EBPA (2.66 mmol, 0.85 g), 4-(phenylethynyl)phthalic anhydride (2.9 mmol, 0.72 g) and 42 g NMP. The suspension was stirred for 15 minutes and cooled to 0°C. The diamine 4,4'-oxydiphenylamine (22.71 mmol, 4.55 g) was added all at once. The reaction mixture was stirred at 0°C for 1 hour under a nitrogen atmosphere, after which the ice bath was removed and the reaction mixture was stirred and warmed to 25°C overnight (about 16 hours).

[0414] Example 5A

[0415] This is an example of preparing a free-standing polyamide-imide film obtained by selectively curing phenylethynyl end groups instead of backbone ethynyl groups. The prepared reactive polyamide-amic acid oligomer solution (10 mL) was poured onto a glass plate and dried under vacuum at 60°C. The temperature was gradually raised to 100°C for 1 hour, 200°C for 1 hour, and 300°C for 1 hour to dehydrate the reactive polyamide-amic acid oligomer to obtain a reactive polyamide-imide oligomer with unreacted phenylethynyl end groups. The temperature was raised to 370°C and the film was kept at this temperature for 1 hour. After the film was cooled to 25°C, a flexible and tough film was obtained. Differential Scanning Calorimetry (N 2 , 10℃ / min) shows T g is 298℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) showed that the storage modulus (E') at 33℃ was 2.3GPa, T g It is 302℃.

[0416] Example 5B

[0417] This is an example of preparing a stand-alone polyamide-imide film with solidified phenylethynyl end groups and backbone ethynyl groups. The prepared reactive polyamide-amic acid oligomer solution (10 mL) was poured onto a glass plate and dried under vacuum at 60°C. The temperature was gradually raised to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to dehydrate the reactive polyamide-amic acid oligomer and obtain a reactive polyamide-imide oligomer with unreacted phenylethynyl end groups. The temperature was raised to 400°C and the film was kept at this temperature for 1 hour. At this temperature, both the phenylethynyl end groups and the backbone ethynyl groups were solidified. After the film was cooled to 25°C, a flexible and tough film was obtained. Thermogravimetric analysis (N 2 , 10°C / min) showed a weight loss of 5% at 453°C. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) showed that the storage modulus (E') at 33℃ was 2.7GPa, T g The stress-strain test at 25°C showed that the Young's modulus of the film was 2.6 GPa, the breaking strength was 78 MPa, and the breaking elongation was 4%.

[0418] Example 6

[0419] Using the ammonium carboxylate pathway to make another M n = 5000 g / mol of a reactive polyamideimide oligomer as shown in Scheme 10 below.

[0420]

[0421] Scheme 10. Synthesis of M via the ammonium carboxylate route n =5000 g / mol fully aromatic reactive polyamideimide oligomer.

[0422] A flame-dried 3-neck 500 mL round-bottom flask equipped with a reflux condenser and a nitrogen inlet connector was charged with 0.2556 mol (49.11 g) of trimellitic anhydride, 0.036 mol (8.94 g) of 4-(phenylethynyl)phthalic anhydride and 85 g of MeOH. The mixture was refluxed at 70° C. for 2 hours under nitrogen. To this mixture was added 0.2730 mol (54.67 g) of 4,4'-oxydiphenylamine in batches. The mixture was refluxed for 24 hours and methanol was removed by evaporation. The resulting carboxylic acid ammonium salt was dried in vacuo at 70° C. The salt was heated to 300° C. at 10° C. / min under nitrogen and kept isothermally at 300° C. for 1 hour at a pressure of 3 atm to obtain a reactive polyamideimide oligomer.

[0423] Thermogravimetric analysis (N 2 , 10℃ / min) showed a weight loss of 5% at 510℃. Differential scanning calorimetry (N2 , 10℃ / min) shows that the T of oligomers before cross-linking g After thermal crosslinking of the reactive oligomer (1 hour at 370°C), T g Increased from 226°C to 287°C. Fourier transform infrared spectroscopy (FTIR) using PerkinElmer Spectroscopy, ATR mode: 1718 cm -1 (Imide C=O), 1660cm -1 (amide C=O) and 1374 cm -1 (Imide CN).

[0424] Example 7

[0425] The preparation of reactive polyamideimide (PAI) oligomers by melt oligomerization is illustrated in Scheme 11 below. Phenylethynyl end-capping agent (PEPA) was used to prepare M n It is a reactive oligomer of 5000 g / mol.

[0426]

[0427] Scheme 11. Synthesis of M with phenylethynyl reactive end groups by melt polymerization n =5000 g / mol fully aromatic reactive polyamideimide oligomer.

[0428] A 500 mL 2-neck round bottom flask equipped with an overhead stirrer and a nitrogen inlet tube was charged with 1,3-phenylenediamine (63.8 mmol, 6.9 g), 4,4'-oxydiphenylamine (163.3 mmol, 32.7 g), trimellitic anhydride (212.8 mmol, 40.9 g), 4-(phenylethynyl)phthalic anhydride (29 mmol, 7.2 g) and 200 mL glacial acetic acid. The resulting reaction mixture was heated at reflux for 2 hours, then 20 mL of acetic anhydride was added and the reaction was refluxed for another hour. The acetic acid formed during the reaction, residual acetic anhydride and water were removed by vacuum distillation. The resulting yellow monomer mixture was fed into an Xplore twin-screw extruder with venting capability at 290°C. The melt was circulated in the extruder at 290°C and 50 rpm for 55 minutes for polymerization. The polymerization was monitored by measuring the relationship between the axial force (N) and time (min), as Figure 3 When the axial force of 5000N was reached (55min), the polymerization was judged to be complete. At this point, the reactive PAI oligomer was extruded as a continuous amber filament and analyzed.

[0429] To confirm that reactive oligomers rather than cross-linked material were obtained, a small sample was dissolved in NMP. GPC analysis against polystyrene standards showed M nThe viscosity of the resulting filaments was 4500 and the polydispersity index (PDI) was 2.22. TGA was run on the resulting filaments at 10°C / min under nitrogen and showed a 1% mass loss at 395°C and a 5% mass loss at 448°C. The powder samples were compressed in a 13 mm tablet press die and subjected to oscillatory shear ramping from 30°C to 350°C at 0.03% strain and 2 rad / s at a ramp rate of 10°C / min. The lowest viscosity recorded was 33000 Pa·s.

[0430] The filament sample was ground into powder and dissolved in NMP at 20wt% overnight, and then cast into a film with a thickness of about 40μm. The film was cured under vacuum at 40°C for 2 hours, 60°C for 1.5 hours, and 100°C, 200°C, 300°C, and 350°C for 1 hour each. The cured film was subjected to uniaxial deformation and showed an optimal fracture stress of 115MPa at 17% strain and 3GPa modulus. The sample was subjected to uniaxial oscillation heating from 30°C to 400°C at a heating rate of 2°C / min with 0.03% strain and 2rad / s. The sample showed a modulus of 3GPa and a T of 290°C. g .

[0431] Example 8

[0432] This is an example of preparing a nanocomposite membrane containing reduced graphene oxide (rGO) 2-D nanoparticles. Graphene oxide (GO) in NMP (2.26 g of 0.53 wt% colloid) was added dropwise to 3.6 g of 30 wt% 5000 g / mol (M n ) was added to a reactive polyamide-amic acid oligomer solution (the ratio of GO to resin = 1:10) and stirred. After stirring for 1 hour, the reactive polyamide-amic acid oligomer graphene oxide solution (4 mL) was cast on a glass plate and dried at 40°C for 2 hours and vacuum dried at 60°C for 2 hours. The temperature was gradually increased to 100°C for 1 hour, 200°C for 1 hour and 300°C for 1 hour to obtain a reactive polyamide-imide oligomer-reduced graphene oxide nanocomposite with unreacted phenylethynyl end groups. During the heating process, GO undergoes partial thermal reduction to form rGO due to the elimination of oxygen groups. The temperature was increased to 370°C, and the nanocomposite film was kept at this temperature for 1 hour. After cooling to 25°C, a flexible nanocomposite film was obtained.

[0433] Differential Scanning Calorimetry (DSC) 2 , 10℃ / min) shows T g is 296℃. Dynamic mechanical thermal analysis (N 2 , 10℃ / min, 1Hz) shows that the storage modulus (E') is 5.8GPa at 35℃ and 2.5GPa at 300℃, Tg The stress-strain test (25°C) showed that the film had a Young's modulus of 5.0 GPa, a fracture strength of 65 MPa, and a fracture strain of 1.32%.

[0434] Nanocomposite films containing reduced graphene oxide (rGO) 2-D nanoparticles can also be prepared using the esters of the reactive polyamide amic acid oligomers of Example 1A. In addition, amine solvents (e.g., acrylic amines) can be used instead of NMP to disperse GO. Such GO dispersions can be mixed with reactive polyamide amic acid oligomer solutions (such as in this example) or reactive polyamide amic acid oligomer ester solutions.

[0435] Example 9

[0436] This is an example of preparing a 4-layer composite material of continuous carbon fiber by prepreg route. n ) reactive polyamide amic acid oligomer solution (fiber resin ratio = 60:40) was impregnated with four (4) layers (20×20 cm) of plain woven carbon fiber fabric T650. After allowing the NMP to evaporate (vacuum, 50°C), the prepreg was heated in a vacuum oven to convert the reactive polyamide amic acid oligomer into a closed-ring reactive polyamideimide oligomer. The thermal profile used was: 100°C for 1 hour, 200°C for 1 hour, and 300°C for 1 hour. The 4 layers were stacked on a KAPTON coated with a high temperature release agent (MARBOCOTE 227). TM foil (50 μm) and placed between two steel plates of a parallel plate press, such as Figure 1 shown.

[0437] The parallel plate press is heated to 300°C and the stack (e.g. Figure 1 The stack was consolidated with a pressure of 5 tons. Within 15 minutes, the temperature was raised to 370°C and after 10 minutes at 370°C, the pressure was raised to 30 tons. The stack was kept at 370°C / 30 tons for 30 minutes, after which the heater was turned off and the stack was allowed to cool to 25°C. A hard and firm panel was obtained which showed a distinct metallic sound. No resin was discharged from the panel.

[0438] Example 10

[0439] This is an example of preparing a continuous carbon fiber 5-layer composite material by melt infusion of resin powder. Five (5) layers (20×20 cm) of plain woven carbon fiber fabric T650 were mixed with 7 g of fully imidized 5000 g / mol (M n) reactive polyamide amide oligomer powder (about 20 μm) was placed between each layer. Five layers were stacked on KAPTONTM foil (50 μm) coated with a high temperature release agent (MARBOCOTE 227) and placed between two steel plates of a parallel plate press. The parallel plate press was heated to 375°C and the stack was placed in the press. The stack was consolidated with a pressure of 5 tons. Within 15 minutes, the pressure was increased from 5 tons to 25 tons and the stack was kept at this pressure and 375°C for 45 minutes, after which the heater was turned off and the stack was allowed to cool to 25°C. A well-consolidated panel was obtained with no resin expelled from the panel.

[0440] The reactive oligomers described herein, ie, reactive polyamideimide oligomers and reactive polyamideamic acid oligomers, may also be referred to as "macromers."

[0441] As used herein, "crosslinkable monomer" refers to a monomer that is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent and has unreacted functional groups that are capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0442] As used herein, "crosslinkable endcapping agent" refers to an endcapping agent that is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and has at least one unreacted functional group capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0443] As used herein, "non-crosslinkable end-capping agent" refers to an end-capping agent that is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, but has no unreacted functional groups that are capable of chain extension and crosslinking after the reactive polyamideimide oligomer is formed.

[0444] As used herein, curing refers collectively to any combination of chain extension, branching, and crosslinking that results in enhanced thermomechanical properties. Curing can be initiated by heat, actinic (electromagnetic) radiation, or electron beam radiation. The terms "thermal curing," "thermal post-treatment," and "thermal post-curing" are used interchangeably for curing initiated by heat.

[0445] The terms "acetylene" and "alkyne" are used interchangeably herein.

[0446] The terms “additive manufacturing” and “3D printing” are used interchangeably in this article.

[0447] The terms "fused filament fabrication" and "fused deposition modeling" are used interchangeably herein.

[0448] As used herein, "at least one of" in conjunction with a list means that the list includes each element individually, as well as combinations of two or more elements of the list and combinations of at least one element of the list with unnamed similar elements.

[0449] The compositions, methods and articles may alternatively comprise, consist of or consist essentially of any suitable material, step or component disclosed herein. The compositions and methods may additionally or alternatively be formulated to be free of or substantially free of any material (or type), step or component that is not necessary to achieve the function or purpose of the compositions and methods.

[0450] All ranges disclosed herein include endpoints, and the endpoints can be independently combined with each other (e.g., "less than or equal to 25 wt.%, or more specifically, 5 wt.% to 20 wt.%" includes all intermediate values ​​of the endpoints and ranges, including, for example, "5 wt.% to 25 wt.%"). References herein to "about" a certain value or parameter include (and describe) embodiments for the value or parameter itself. In certain embodiments, the term "about" includes an indication of ±50%. In certain other embodiments, the term "about" includes an indication of ±20%. In certain other embodiments, the term "about" includes an indication of ±10%. In other embodiments, the term "about" includes an indication of ±5%. In certain other embodiments, the term "about" includes an indication of ±1%. In certain other embodiments, the term "about" includes an indication of ±0.5%, and in certain other embodiments, 0.1%. Such changes are suitable for performing the disclosed method or employing the disclosed composition. In addition, the term "about x" includes a description of "x".

[0451] "Combination" includes blends, mixtures, alloys, reaction products, and the like. Unless otherwise indicated herein or clearly contradicted by context, the terms "a", "an", and "the" do not denote a limitation of quantity, and should be construed to cover both the singular and the plural. Unless expressly stated otherwise, "or" means "and / or".

[0452] References throughout this specification to "some embodiments," "one embodiment," etc. mean that a particular element described in conjunction with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. Furthermore, it should be understood that the described elements may be combined in any suitable manner in the various embodiments.

[0453] Unless otherwise defined, technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. All cited patents, patent applications and other references are incorporated herein by reference in their entirety. However, if a term in this application contradicts or conflicts with a term incorporated in a reference, the term in this application takes precedence over the conflicting term incorporated in the reference.

[0454] Although specific embodiments have been described, the applicant or other persons skilled in the art may think of alternatives, modifications, variations, improvements, and substantial equivalents that are not currently foreseeable or may not be foreseeable. Therefore, the appended aspects submitted, and since they can be modified, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A reactive polyamideimide oligomer comprising units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least two cross-linkable end-capping agents, wherein the at least two cross-linkable end-capping agents are reactive at different temperature ranges; wherein the crosslinkable end-capping agent is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and each crosslinkable end-capping agent has at least one unreacted functional group capable of thermal chain extension and crosslinking after formation of the reactive polyamideimide oligomer; The crosslinkable end-capping agent is at least two of the following: wherein the reactive polyamideimide oligomer is prepared by a process comprising: simultaneously stepwise polymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and at least two cross-linkable end-capping agents; wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is selected from the group consisting of: at least one aromatic tri-functional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; The number average molecular weight M of the reactive polyamideimide oligomer is n 1000 to 10000 g / mol calculated using the Carothers equation; and The reactive polyamideimide oligomer has a melt complex viscosity of 1000 to 100000 Pa·s at 360° C., which is measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10° C. / min, a frequency of 2 rad / s, and a strain of 0.03% to 1.0%.

2. The reactive polyamideimide oligomer according to claim 1, wherein the reactive polyamideimide oligomer is derived from a reactive polyamideamic acid oligomer intermediate by cyclodehydration, and greater than 80% and less than or equal to 100% of the amic acid groups in the reactive polyamideamic acid intermediate are imidized.

3. The reactive polyamideimide oligomer according to claim 1, wherein the reactive polyamideimide oligomer is derived from a reactive polyamideamic acid oligomer intermediate by cyclodehydration, and greater than or equal to 20% and less than or equal to 80% of the amic acid groups in the reactive polyamideamic acid intermediate are imidized.

4. The reactive polyamideimide oligomer of claim 1, wherein the at least one aromatic diamine is two aromatic diamines.

5. The reactive polyamideimide oligomer according to claim 1, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

6. The reactive polyamideimide oligomer according to claim 1, wherein the aromatic diamine is at least one of: 7 . The reactive polyamideimide oligomer according to claim 1 , wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4′-oxydiphenylamine, or 3,4′-oxydiphenylamine.

8. The reactive polyamideimide oligomer according to claim 1, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent is at least one of:

9. The reactive polyamideimide oligomer according to claim 1, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent is at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

10. The reactive polyamideimide oligomer according to claim 1, wherein the unreacted functional group is at least one of an ethynyl group, a methylethynyl group, a phenylethynyl group, a ketoethynyl group, a propargyl ether group, a norbornene group, a maleimide group, a cyanate group, a phthalonitrile group, a benzocyclobutenyl group, a biphenyl group or a benzoxazine group.

11. The reactive polyamideimide oligomer according to claim 1, wherein the cross-linkable end-capping agent is at least two of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride or 4-phenylethynylphthalic anhydride.

12. The reactive polyamideimide oligomer according to claim 1, comprising two cross-linkable end-capping agents having reactivity in different temperature ranges.

13. The reactive polyamideimide oligomer of claim 1, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof. 14 . The reactive polyamideimide oligomer according to claim 13 , wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline. 15 . The reactive polyamideimide oligomer according to claim 1 , further comprising a unit derived from at least one of an aromatic triamine, an aromatic tricarboxylic acid, or an aromatic tricarboxylic acid chloride.

16. A reactive polyamideimide oligomer comprising units derived from: At least one aromatic diamine selected from the group consisting of: An aromatic di-, tri- or tetrafunctional carboxylic acid or a functional equivalent thereof selected from the group consisting of: at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; Wherein the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent is selected from at least one of the following: as well as At least two cross-linkable end-capping agents selected from the group consisting of: wherein the reactive polyamideimide oligomer does not contain units derived from (acetylene-1,2-diyl)diphthalic dianhydride; wherein the reactive polyamideimide oligomer is prepared by a process comprising: simultaneously stepwise polymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and at least two cross-linkable end-capping agents; The number average molecular weight M of the reactive polyamideimide oligomer is n 1000 to 10000 g / mol calculated using the Carothers equation; and The reactive polyamideimide oligomer has a melt complex viscosity of 1000 to 100000 Pa·s at 360° C., which is measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10° C. / min, a frequency of 2 rad / s, and a strain of 0.03% to 1.0%.

17. The reactive polyamideimide oligomer according to claim 16, comprising units derived from: At least one aromatic diamine selected from 1,3-phenylenediamine, 4,4'-oxydiphenylamine or 3,4'-oxydiphenylamine; a di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride; and At least two cross-linkable end-capping agents selected from the group consisting of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, and 4-phenylethynylphthalic anhydride.

18. A method for producing a reactive polyamideimide oligomer according to any one of claims 1 to 17, the method comprising: copolymerizing the at least one aromatic diamine, the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent, and the at least two cross-linkable end-capping agents by simultaneous stepwise polymerization in the presence of a polar solvent to form a reactive polyamide amic acid oligomer; and heating the reactive polyamide amic acid oligomer at a temperature and for a time sufficient to prepare the reactive polyamide imide oligomer; The at least two cross-linkable end-capping agents are reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each cross-linkable end-capping agent has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamideimide oligomer is formed.

19. The manufacturing method of claim 18, wherein the temperature and time sufficient to prepare the reactive polyamideimide oligomer are 140°C to 220°C for 1 minute to 120 minutes. 20 . The production method according to claim 18 , wherein the polar solvent is at least one of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane.

21. The manufacturing method according to claim 18, further comprising removing the polar solvent from the reactive polyamideamic acid oligomer before heating the reactive polyamideamic acid oligomer at a temperature and for a time sufficient to prepare the reactive polyamideimide oligomer.

22. The manufacturing method of claim 21, wherein the temperature and time sufficient to prepare the reactive polyamideimide oligomer are 220°C to 300°C for 1 minute to 120 minutes.

23. The manufacturing method according to claim 18, wherein the method further comprises adding toluene to the reactive polyamide amic acid oligomer and azeotropically distilling toluene and water.

24. The manufacturing method of claim 18, wherein the method further comprises heating the reactive polyamide amic acid oligomer in the presence of acetic anhydride and a catalytic amount of a tertiary amine.

25. The manufacturing method according to claim 18, wherein the method further comprises irradiating the reactive polyamide amic acid oligomer with microwaves. The production method according to claim 18 , wherein the copolymerization is carried out in the presence of a phosphorylating agent and a catalytic amount of a salt.

27. A method for producing a reactive polyamideimide oligomer according to any one of claims 1 to 17, the method comprising: In water or C 1-4 heating the at least one aromatic diamine, the at least one aromatic di-, tri-, or tetra-functional carboxylic acid or a functional equivalent thereof, and the at least two cross-linkable capping agents in the presence of at least one of an alcohol at a temperature and for a time sufficient to form at least one reactive carboxylic acid ammonium salt; Optionally remove excess water or C 1-4 Alcohol; and heating the reactive carboxylate ammonium salt at a temperature and for a time sufficient to form the reactive polyamideimide oligomer; The at least two cross-linkable end-capping agents are reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each cross-linkable end-capping agent has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamideimide oligomer is formed.

28. The method of claim 27, comprising reactively extruding the reactive carboxylic acid ammonium salt at a temperature and for a time sufficient to form the reactive polyamideimide oligomer.

29. The method of claim 27, comprising dissolving the reactive carboxylic acid ammonium salt in a polar solvent prior to heating at a temperature, pressure, and time sufficient to form the reactive polyamideimide oligomer.

30. A method for making a reactive polyamideimide oligomer according to any one of claims 1 to 17, said method comprising reactively extruding said at least one aromatic diamine or an activated derivative thereof, said at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and said at least two cross-linkable end-capping agents at a temperature and for a time sufficient to prepare said reactive polyamideimide oligomer; The at least two cross-linkable end-capping agents are reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each cross-linkable end-capping agent has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamideimide oligomer is formed.

31. The manufacturing method according to claim 30, wherein the reactive extrusion is performed in the presence of a polar solvent, and the polar solvent is removed by distillation during the reactive extrusion.

32. The manufacturing method according to claim 30, wherein the reactive extrusion is performed in the presence of an acidic catalyst.

33. The manufacturing method of claim 32, wherein the acid catalyst is acetic acid and the acetic acid is removed by distillation during the reactive extrusion.

34. The manufacturing method according to claim 30, wherein the reactive extrusion is performed in the presence of acetic anhydride, and the acetic anhydride is removed by distillation during the reactive extrusion.

35. The manufacturing method according to claim 30, wherein the reactive extrusion is performed in a melt extruder having a plurality of preset heating zones equipped with vents.

36. A blend composition comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17 and a thermoplastic polymer.

37. A powder coating composition comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17.

38. A reactive adhesive composition comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17.

39. A high temperature elastomeric composition prepared by heating the reactive polyamideimide oligomer according to any one of claims 1 to 17 at a temperature and for a time sufficient to crosslink the reactive polyamideimide oligomer.

40. A high temperature foam comprising the reactive polyamideimide oligomer of any one of claims 1 to 17.

41. A method of compounding the reactive polyamideimide oligomer of any one of claims 1 to 17, comprising mixing the reactive polyamideimide oligomer with at least one other material at a temperature and for a time sufficient to melt but not crosslink the reactive polyamideimide oligomer.

42. A method of making an article, the method comprising heating the reactive polyamideimide oligomer according to any one of claims 1 to 17 at a sufficient temperature and for a sufficient time to shape and crosslink the reactive polyamideimide oligomer.

43. The method of manufacture according to claim 42, wherein the sufficient temperature and time is 300 to 450°C for 1 to 60 minutes.

44. The method of manufacturing according to claim 42, wherein the method is additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting or forging.

45. The manufacturing method according to claim 44, wherein the injection molding is reaction injection molding and the casting is solution casting.

46. ​​An article made by the method of claim 42.

47. An article comprising the reactive polyamideimide oligomer of any one of claims 1 to 17.

48. The article of claim 47, wherein the reactive polyamideimide oligomer is cross-linked.

49. The manufacturing method according to claim 44, wherein the method is fiber reinforced composite material manufacturing.

50. The method of claim 49, comprising heating at least one layer of fiber fabric and at least one layer of reactive polyamideimide oligomer as a powder or film at sufficient temperature, pressure, and time to melt the reactive polyamideimide oligomer, impregnate the fiber fabric, and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

51. The method of claim 50, comprising: impregnating at least one layer of fiber fabric with a solution of a reactive polyamideimide oligomer dissolved in a polar solvent; The polar solvent was removed under reduced pressure; as well as Heating is performed at sufficient temperature, pressure, and time to crosslink the reactive polyamideimide oligomer and form a fiber reinforced composite material.

52. A fiber-reinforced composite material produced by the method according to claim 49.

53. A fiber-reinforced composite material comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17.

54. The fiber reinforced composite material of claim 53, wherein the reactive polyamideimide oligomer is cross-linked.

55. The fiber-reinforced composite material of claim 52, wherein the composite material is a multi-layer carbon-reinforced composite material.

56. The method of manufacturing according to claim 44, wherein the method is pultrusion for manufacturing a unidirectional tape.

57. A unidirectional tape prepared by the method according to claim 56.

58. A unidirectional tape comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17.

59. The unidirectional tape of claim 58, wherein the reactive polyamideimide oligomer is cross-linked.

60. The manufacturing method according to claim 44, wherein the method is solution spinning or melt spinning of fibers.

61. A fiber produced by the method according to claim 60.

62. A fiber comprising the reactive polyamideimide oligomer of any one of claims 1 to 17.

63. The fiber of claim 62, wherein the reactive polyamideimide oligomer is cross-linked.

64. The method of manufacturing according to claim 44, wherein the method is additive manufacturing.

65. A manufacturing method according to claim 64, wherein the method is fused filament manufacturing, the method comprising extruding the reactive polyamideimide oligomer in adjacent horizontal layers so that there is an interface between each polyamideimide oligomer layer, and exposing the layers to heat at a temperature and for a time sufficient to cause the reactive polyamideimide oligomer to crosslink and form an article.

66. The method of manufacturing according to claim 64, wherein the method is selective laser sintering, the method comprising selectively sintering and cross-linking particles of the reactive polyamideimide oligomer with a laser to form an article.

67. The manufacturing method of claim 64, wherein the method is directed energy deposition or laser engineered net shaping.

68. An article made by the method of claim 64.

69. An additively manufactured article comprising the reactive polyamideimide oligomer of any one of claims 1 to 17.

70. The additively manufactured article of claim 69, wherein the reactive polyamideimide oligomer is cross-linked.

71. The method of manufacturing according to claim 45, wherein the method is solution casting and comprises: casting a solution of a reactive polyamideimide oligomer dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive polyamideimide oligomer film; as well as The polyamideimide oligomer film is heated at a temperature and for a time sufficient to crosslink the polyamideimide oligomer and form a flexible film.

72. A flexible membrane manufactured by the solution casting method according to claim 71.

73. A flexible film comprising the reactive polyamideimide oligomer according to any one of claims 1 to 17.

74. The flexible film of claim 72, wherein the reactive polyamideimide oligomer is cross-linked.

75. The flexible film of claim 74, wherein the flexible film exhibits at least one of the following: The glass transition temperature T was measured by differential scanning calorimetry at a heating rate of 10 °C / min under N2. g 280 to 310°C; The storage modulus E' was 2.2 to 3.4 GPa as measured by dynamic mechanical thermal analysis under N2 at a heating rate of 10 °C / min and an oscillation rate of 1 Hz; The Young's modulus is 3.0 to 3.8 GPa, the breaking strength is 130 to 160 MPa, or the breaking strain is 10 to 80%, all measured at 25°C.

76. The method of manufacturing according to claim 44, wherein the method is injection molding.

77. An injection molded article produced by the method according to claim 76.

78. An injection molded article comprising the reactive polyamideimide oligomer of any one of claims 1 to 17.

79. The injection molded article of claim 78, wherein the reactive polyamideimide oligomer is cross-linked.

80. A reactive polyamide amic acid oligomer comprising units derived from at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least two cross-linkable end-capping agents, the at least two cross-linkable end-capping agents being reactive at different temperature ranges, wherein the crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof and each crosslinkable end-capping agent has at least one unreacted functional group capable of chain extension and crosslinking after formation of the reactive polyamide amic acid oligomer; The crosslinkable end-capping agent is at least two of the following: wherein the reactive polyamide amic acid oligomer is prepared by a process comprising: simultaneously stepwise polymerizing the at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and the at least two cross-linkable end-capping agents; Wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent is selected from the following group: at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; The number average molecular weight M of the reactive polyamide amic acid oligomer is n 1000 to 10000 g / mol calculated using the Carothers equation; and The reactive polyamide amic acid oligomer can be cyclodehydrated to form a reactive polyamideimide, and the melt complex viscosity of the reactive polyamideimide oligomer at 360°C is 1000 to 100000 Pa·s, and the melt complex viscosity is measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10°C / min, a frequency of 2 rad / s and a strain of 0.03% to 1.0%.

81. The reactive polyamide amic acid oligomer of claim 80, wherein 0% to 20% of the amic acid groups are imidized.

82. The reactive polyamide amic acid oligomer of claim 80, wherein each cross-linkable end-capping agent has an unreacted functional group capable of thermal chain extension and cross-linking after cyclodehydration to form the reactive polyamideimide oligomer.

83. The reactive polyamide amic acid oligomer of claim 80, wherein the at least one aromatic diamine is two aromatic diamines.

84. The reactive polyamide amic acid oligomer of claim 80, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

85. The reactive polyamide amic acid oligomer of claim 80, wherein the aromatic diamine is at least one of:

86. The reactive polyamide amic acid oligomer of claim 80, wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine.

87. The reactive polyamide amic acid oligomer of claim 80, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of:

88. The reactive polyamide amic acid oligomer of claim 80, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or its functional equivalent is at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

89. The reactive polyamide amic acid oligomer of claim 80, wherein the at least one unreacted functional group is at least one of an acetylene group, a methylacetylene group, a phenylacetylene group, a ketoacetylene group, a propargyl ether group, a norbornene group, a maleimide group, a cyanate group, a phthalonitrile group, a benzocyclobutenyl group, a biphenyl group, or a benzoxazine group.

90. The reactive polyamide amic acid oligomer of claim 80, wherein the cross-linkable end-capping agent is at least two of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, or 4-phenylethynylphthalic anhydride.

91. The reactive polyamide amic acid oligomer of claim 80, comprising two cross-linkable end-capping agents having reactivity in different temperature ranges.

92. The reactive polyamide amic acid oligomer of claim 80, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with the at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof.

93. The reactive polyamide amic acid oligomer of claim 92, wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride or aniline.

94. A reactive polyamide amic acid oligomer comprising units derived from: At least one aromatic diamine selected from the group consisting of: A di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of the following: and at least two crosslinkable end-capping agents selected from the group consisting of: wherein the reactive polyamideimide oligomer does not contain units derived from (acetylene-1,2-diyl)diphthalic dianhydride; wherein the reactive polyamide amic acid oligomer is prepared by a process comprising: simultaneously stepwise polymerizing at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent and at least two cross-linkable end-capping agents; Wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent is selected from the following group: at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; The number average molecular weight M of the reactive polyamide amic acid oligomer is n 1000 to 10000 g / mol calculated using the Carothers equation; and The reactive polyamide amic acid oligomer can be cyclodehydrated to form a reactive polyamideimide, and the melt complex viscosity of the reactive polyamideimide oligomer at 360°C is 1000 to 100000 Pa·s, and the melt complex viscosity is measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10°C / min, a frequency of 2 rad / s and a strain of 0.03% to 1.0%.

95. The reactive polyamide amic acid oligomer of claim 94 comprising units derived from: At least one aromatic diamine selected from 1,3-phenylenediamine, 4,4'-oxydiphenylamine or 3,4'-oxydiphenylamine; a di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride; and At least two cross-linkable end-capping agents selected from the group consisting of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, and 4-phenylethynylphthalic anhydride.

96. A method for producing a reactive polyamide amic acid oligomer according to any one of claims 80 to 95, the method comprising: copolymerizing the at least one aromatic diamine, the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and the at least two cross-linkable end-capping agents in the presence of a polar solvent to form the reactive polyamide amic acid oligomer; The at least two cross-linkable end-capping agents are reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each cross-linkable end-capping agent has at least one unreacted functional group capable of chain extension and cross-linking after the reactive polyamide amic acid oligomer is formed.

97. The manufacturing method according to claim 96, wherein the polar solvent is at least one of water, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene or sulfolane.

98. The manufacturing method according to claim 97, further comprising separating the reactive polyamide amic acid oligomer from a polar solvent.

99. A blend composition comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95 and a thermoplastic polymer.

100. A powder coating composition comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

101. A reactive adhesive composition comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

102. A high temperature foam comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

103. A method of compounding the reactive polyamide amic acid oligomer of any one of claims 80 to 95, comprising mixing the reactive polyamide amic acid oligomer with at least one other material at a temperature and for a time sufficient to imidize the reactive polyamide amic acid oligomer without crosslinking.

104. A method of making an article, the method comprising heating the reactive polyamide amic acid oligomer according to any one of claims 80 to 95 at a sufficient temperature and for a sufficient time to imidize, shape and crosslink the reactive polyamide amic acid oligomer.

105. The manufacturing method of claim 104, wherein the sufficient temperature and time are 300 to 400°C for 10 to 60 minutes.

106. The manufacturing method of claim 104, wherein the method is additive manufacturing, fiber reinforced composite manufacturing, pultrusion, fiber spinning, compression molding, injection molding, blow molding, rotational molding, transfer molding, foam molding, thermoforming, casting or forging.

107. The manufacturing method according to claim 106, wherein the injection molding is reaction injection molding and the casting is solution casting.

108. An article manufactured by the method according to any one of claims 104.

109. An article comprising the reactive polyamide amic acid oligomer of any one of claims 80 to 95.

110. The manufacturing method according to claim 106, wherein the method is fiber reinforced composite material manufacturing.

111. The method of claim 110, comprising heating at least one layer of fiber fabric and at least one layer of reactive polyamide amic acid oligomer as a powder or film at sufficient temperature, pressure and time to imidize the reactive polyamide amic acid oligomer, impregnate the fiber fabric, and crosslink to form a fiber reinforced composite material.

112. The method of claim 111, comprising: impregnating at least one layer of fiber fabric with a solution of reactive polyamide amic acid oligomer dissolved in a polar solvent; The polar solvent is removed under reduced pressure, and The heating is carried out at a temperature, pressure and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomers to form a fiber reinforced composite material.

113. A fiber-reinforced composite material produced by the method according to claim 110.

114. A fiber-reinforced composite material comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

115. The fiber-reinforced composite material of claim 114, wherein the composite material is a multi-layer carbon-reinforced composite material.

116. The method of manufacturing according to claim 106, wherein the method is pultrusion for manufacturing a unidirectional tape.

117. A unidirectional tape prepared by the method of claim 116.

118. A unidirectional tape comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

119. The manufacturing method according to claim 106, wherein the method is solution spinning or melt spinning of fibers.

120. A fiber produced by the method of claim 119.

121. A fiber comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

122. The method of manufacturing according to claim 106, wherein the method is additive manufacturing.

123. A manufacturing method according to claim 122, wherein the method is fused filament manufacturing, the method comprising extruding the reactive polyamide amic acid oligomer in adjacent horizontal layers so that there is an interface between each reactive polyamide amic acid oligomer layer, and exposing the layers to heat at a temperature and time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer and form the article.

124. The manufacturing method of claim 122, wherein the method is selective laser sintering, the method comprising selectively sintering, imidizing and cross-linking particles of the reactive polyamide amic acid oligomer with a laser to form an article.

125. The manufacturing method of claim 122, wherein the method is directed energy deposition or laser engineered net shaping.

126. An article manufactured by the method of claim 125.

127. An additively manufactured article comprising the reactive polyamide amic acid oligomer of any one of claims 80 to 95.

128. The method of manufacturing according to claim 107, wherein the method is solution casting and comprises: casting a solution of a reactive polyamide amic acid oligomer dissolved in a polar solvent onto a mold; removing the solvent to form a reactive polyamide amic acid oligomer film; as well as The reactive polyamide amic acid oligomer film is heated at a temperature and for a time sufficient to imidize and crosslink the reactive polyamide amic acid oligomer and form a flexible film.

129. A flexible membrane manufactured by the solution casting method according to claim 128.

130. A flexible film comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

131. The method of manufacturing according to claim 106, wherein the method is injection molding.

132. An injection molded article produced by the method according to claim 131.

133. An injection molded article comprising the reactive polyamide amic acid oligomer according to any one of claims 80 to 95.

134. The method of manufacture of claim 106, wherein the method is blow molding.

135. A reactive ammonium carboxylate salt formed by a process comprising: In C 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof, and at least two crosslinkable endcapping agents in the presence of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; Removal of excess C 1-4 alcohol; wherein the crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each crosslinkable end-capping agent has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt, The crosslinkable end-capping agent is at least two of the following: Wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent is selected from the following group: at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; The reactive carboxylic acid ammonium salt has a melt complex viscosity of 1 to 100 Pa·s between 80°C and 120°C, the melt complex viscosity being measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10°C / min, a frequency of 2 rad / s, and a strain of 0.03% to 1.0%.

136. The reactive ammonium carboxylate salt of claim 135, wherein the at least one aromatic diamine is two aromatic diamines.

137. The reactive carboxylate ammonium salt of claim 135, wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or a functional equivalent thereof is two aromatic di-, tri- or tetra-functional carboxylic acids or a functional equivalent thereof.

138. The reactive ammonium carboxylate salt of claim 135, wherein the aromatic diamine is at least one of:

139. The reactive ammonium carboxylate salt of claim 135, wherein the aromatic diamine is at least one of 1,3-phenylenediamine, 4,4'-diphenylamine oxide, or 3,4'-diphenylamine oxide.

140. The reactive carboxylate ammonium salt of claim 135, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of:

141. The reactive carboxylate ammonium salt of claim 135, wherein the di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof is at least one of trimellitic anhydride, isophthalic anhydride, pyromellitic dianhydride or biphenyltetracarboxylic dianhydride.

142. The reactive ammonium carboxylate salt of claim 135, wherein the unreacted functional group is at least one of an ethynyl group, a methylethynyl group, a phenylethynyl group, a ketoethynyl group, a propargyl ether group, a norbornene group, a maleimide group, a cyanate group, a phthalonitrile group, a benzocyclobutenyl group, a biphenyl group, or a benzoxazinyl group.

143. The reactive carboxylate ammonium salt of claim 135, wherein the cross-linkable end-capping agent is at least two of 4-ethynyl phthalic anhydride, 4-methylethynyl phthalic anhydride, or 4-phenylethynyl phthalic anhydride.

144. The reactive ammonium carboxylate salt of claim 135 comprising two cross-linkable capping agents having reactivity at different temperature ranges.

145. The reactive carboxylate ammonium salt of claim 135, further comprising units derived from at least one non-crosslinkable end-capping agent, wherein the non-crosslinkable end-capping agent is reactive with at least one aromatic diamine or at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof.

146. The reactive carboxylate ammonium salt of claim 145, wherein the non-crosslinkable end-capping agent is at least one of benzoic acid, benzoyl chloride, phthalic anhydride, or aniline.

147. A reactive ammonium carboxylate salt comprising units derived from: At least one aromatic diamine selected from the group consisting of: A di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of the following: and at least two crosslinkable end-capping agents selected from the group consisting of: Wherein the at least one aromatic di-, tri- or tetra-functional carboxylic acid or its functional equivalent is selected from the following group: at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof; at least one aromatic difunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; and at least one aromatic difunctional carboxylic acid or a functional equivalent thereof, at least one aromatic trifunctional carboxylic acid or a functional equivalent thereof, and at least one aromatic tetrafunctional carboxylic acid or a functional equivalent thereof; wherein functional equivalents of carboxylic acids include carboxylic acid esters, carboxylic acid halides and carboxylic acid anhydrides; and The reactive carboxylic acid ammonium salt can be polymerized and imidized to form a polyamideimide having a melt complex viscosity of 1000 to 100000 Pa·s at 360° C., the melt complex viscosity being measured by oscillatory shear rheology between parallel plates under N2 at a heating rate of 10° C. / min, a frequency of 2 rad / s, and a strain of 0.03% to 1.0%.

148. The reactive carboxylic acid ammonium salt of claim 135, comprising units derived from: an aromatic diamine selected from at least one of 1,3-phenylenediamine, 4,4'-oxydiphenylamine, or 3,4'-oxydiphenylamine; a di-, tri-, or tetra-functional aromatic carboxylic acid or a functional equivalent thereof selected from at least one of trimellitic anhydride, 4-chloroformylphthalic anhydride, isophthalic anhydride, isophthalic dichloride, pyromellitic dianhydride, or biphenyltetracarboxylic dianhydride; and a cross-linkable end-capping agent selected from at least two of 4-ethynylphthalic anhydride, 4-methylethynylphthalic anhydride, or 4-phenylethynylphthalic anhydride.

149. A method for producing a reactive ammonium carboxylate salt according to claims 135 to 148, the method comprising: In C 1-4 heating at least one aromatic diamine, at least one aromatic di-, tri- or tetra-carboxylic acid or a functional equivalent thereof, and at least two crosslinkable endcapping agents in the presence of an alcohol at a temperature and for a time sufficient to form a reactive carboxylic acid ammonium salt; Removal of excess C 1-4 alcohol; wherein the crosslinkable end-capping agent is reactive with the at least one aromatic diamine or the at least one di-, tri- or tetra-functional aromatic carboxylic acid or a functional equivalent thereof, and each crosslinkable end-capping agent has at least one unreacted functional group capable of chain extension and crosslinking after the formation of the reactive carboxylic acid ammonium salt.

150. A method of compounding the reactive ammonium carboxylate salt of any one of claims 135 to 148, comprising mixing the reactive ammonium carboxylate salt with at least one other material at a temperature, pressure and time sufficient to produce but not crosslink a reactive polyamideimide oligomer.

151. A method of making an article, the method comprising heating the reactive carboxylate ammonium salt of any one of claims 135 to 148 at sufficient temperature, pressure and time to prepare, shape and crosslink a reactive polyamideimide oligomer.

152. The method of manufacturing according to claim 151, wherein the sufficient temperature, pressure and time are 300°C to 400°C, 0 to 300 MPa and 10 to 60 minutes.

153. The manufacturing method of claim 151, wherein the method is fiber reinforced composite manufacturing, pultrusion, compression molding, injection molding or solution casting.

154. An article manufactured by the method according to claim 151.

155. The manufacturing method of claim 151, wherein the method is for fiber reinforced composite manufacturing.

156. A method of manufacturing according to claim 155, comprising heating at least one layer of fiber fabric and at least one layer of reactive ammonium carboxylate salt as a powder or film at a temperature, pressure and time sufficient to impregnate the fiber fabric with the reactive ammonium carboxylate salt and prepare and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

157. The manufacturing method according to claim 155, comprising: impregnating at least one layer of fiber fabric with a solution of a reactive ammonium carboxylate salt dissolved in a polar solvent; The polar solvent was removed under reduced pressure; and heating at a temperature, pressure, and time sufficient to polymerize and crosslink the reactive polyamideimide oligomer to form a fiber reinforced composite material.

158. A fiber-reinforced composite material produced by the method of claim 155.

159. The fiber-reinforced composite material of claim 158, wherein the composite material is a multi-layer carbon-reinforced composite material.

160. The method of manufacturing according to claim 153, wherein the method is solution casting and comprises: casting a solution of a reactive ammonium carboxylate salt dissolved in a polar solvent onto a mold; removing the polar solvent to form a reactive ammonium carboxylate salt film; and heating the reactive carboxylate ammonium salt film at a temperature, pressure, and time sufficient to prepare and crosslink the reactive polyamideimide oligomer to form a flexible film.

161. A flexible membrane manufactured by the solution casting method of claim 160.

162. The method of manufacture of claim 153, wherein the method is injection molding.

163. The method of manufacture of claim 151, wherein the method is blow molding.

Images