CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of European Patent Application No. EP

19220138.2 filed in the European Patent Office on December 30, 2019, the entire content of which is incorporated herein by reference.

BACKGROUND

[0001] Polyimides (Pis), which include polyetherimides (PEIs), are high performance polymers having a high glass transition temperature. In particular, PEIs are known to have relatively high strength, heat resistance, and modulus, and broad chemical resistance, and thus are widely used in applications as diverse as automotive, telecommunication, aerospace, electrical/electronics, transportation, and healthcare. Moreover, PEIs can be recycled, whereas some Pis are thermosets that cannot be recycled.

[0002] High-flow glass fiber reinforced PEIs are commercially available and are known for high modulus and impact properties, however, there remains a necessary balancing of desired flow and mechanical properties in such materials. For example, as glass fiber content of the reinforced PEI increases one can witness an unwanted reduction in flow properties with a desired improvement in mechanical properties. The reduction in flow is due to a higher melt viscosity in the glass reinforced PEI and this presents a technical problem in achieving molded articles with acceptable mechanical properties.

[0003] Branched PEI can be produced, for example with 2,4,4’ -triaminodiphenylether (TADE) as a branching agent. Branched PEI exhibits improved flow and shear thinning, but also small reductions in desired mechanical properties in comparison to linear PEI of equivalent molecular weight. See, PCT/US2017/068984 filed December 29, 2017.

[0004] There remains a continuing need in the art for polyimides and polyetherimides that have improved flow properties and desirable mechanical properties.

BRIEF SUMMARY

[0005] Provided is a reinforced polyimide composition comprising 2 to 90 weight percent (wt%), preferably 20 to 70 wt%, more preferably 20 to 50 wt% of a linear polyimide; 2 to 95 wt%, preferably 5 to 70 wt%, more preferably 10 to 40 wt%, of a branched polyimide; and 5 to 50 wt%, preferably 10 to 45 wt%, more preferably 15 to 45 wt% of a reinforcing material, wherein each weight percent is based on a total weight of the polyimide composition.

[0006] Also provided is a polymer composition comprising the reinforced polyimide composition and an additional polymer.

[0007] Further provided is an article comprising the reinforced polyimide composition or the polymer composition.

[0008] The above described and other features are exemplified by the following detailed description.

DETAILED DESCRIPTION

[0009] Compositions including a branched PI or PEI, and a linear PI or PEI, provide branched/linear polyimide compositions with improved properties. As reported, the polyimide compositions including both a linear PEI and a branched PEI exhibit improved melt flow properties and still maintain the mechanical properties associated with linear PEIs. The results demonstrate a synergistic interaction between the linear PEI and branched PEI in the polyimide compositions as the melt flow and mechanical properties were surprisingly better than expected of the aggregate properties of the individual, linear or branched PEI components.

[0010] Such properties are especially useful in the manufacture of thin-wall parts, where high-flow properties, especially low melt viscosity under the high shear conditions are important in injection molding. The branched/linear polyimide compositions can satisfy this criterion and fare better than similar compositions with linear PI of the same molecular weight. The branched/linear polyimide composition can further include additional thermoplastics to provide other useful polymer compositions.

[0011] We describe a reinforced, branched/linear polyimide composition, hereinafter “reinforced polyimide composition” including 2 to 90 weight percent (wt%), preferably 20 to 70 wt%, more preferably 20 to 50 wt% of a linear polyimide; and 2 to 95 wt%, preferably 5 to 70 wt%, more preferably 10 to 40 wt% of a branched polyimide. In some aspects, a weight ratio of the linear polyimide to the branched polyimide is 9:1 to 1:9, or 5:1 to 1:5, or 4:1 to 1:4, or 3:1 to 1:3, or 2:1 to 1:2. The reinforced polyimide composition also includes 5 to 50 wt%, preferably 10 to 45 wt%, more preferably 15 to 45 wt% of a reinforcing material.

[0012] The branched polyimide can be of formula (1) or (1’)

[0013] In formulas (1) and (G), G is a group having a valence of t, present in an amount 0.1 to 20 mol%, or 0.5 to 10 mol%, or 1.0 to 5 mol%, or 1.5 to 4 mol%, and q is 0 or 1, m is 0 or 1, d is 0 or 1, p is 1 or 2, t is 2 to 6, preferably 2 to 4. In an aspect, t is 2, and G is -O-, -C(O)-, - OC(O)-, -(O)CO-, -NHC(O), -(O)CNH-, -S-, -S(O)-, -S(0) ₂ -, or -P(R ^a )(0)- (wherein R ^a is a Ci-s alkyl or C6-12 aryl). In another aspect, t is 3, and G is nitrogen, phosphorus, or P(O). In still another aspect, G is a C1-60 hydrocarbon group having a valence of t. In a preferred aspect, G is - O- as m is 0, pentavalent P(0), a C6-50 hydrocarbon having at least one aromatic group, for example a Ce-AO aromatic hydrocarbon group, a C2-20 aliphatic group, a C4-8 cycloaliphatic group, a C3-12 heteroarylene, or a polymer moiety; or G is -0-, -S(0) ₂ -, pentavalent P(O), a C6-20 aromatic hydrocarbon group, a C2-20 aliphatic group, or a C4-8 cycloaliphatic group. In a specific aspect, G is -O- , pentavalent P(O), or a C6-50 hydrocarbon having at least one aromatic group.

As q, m, and d are 0, G can be a saturated C2-20 aliphatic group, C3-12 heteroarylene or a polymeric moiety, for example an amino resin such as a urea-formaldehyde, a melamine- formaldehyde, or other resin having active amino groups.

[0014] G is a branching group that is present in an amount of 0.01 to 20 mol%, preferably 0.5 to 10 mol%, more preferably 1.0 to 5 mol%, or 1.5 to 4 mol%. In other words, the branched polyimide is derived from 0.01 to 20 mol%, or 0.5 to 10 mol%, or 1.0 to 5 mol%, or 1.5 to 4 mol% of a branching polyamine of formula (5) based on the total moles of amine precursors, wherein the branching polyamine (5) is described in further detail herein. For example, the branched polyimide can include from 0.01 to 20 mol% of diimide units containing G branching groups, based on the total moles of repeating diimide units in the branched polyimide.

[0015] As used herein, the terms “polyamine” and “branching polyamine” are equivalent and refer to an amine compound having three or more moles of amine functionality per mole of polyamine or branching polyamine. It is to be further understood that the number of moles of amine functionality also refers to the number of reactive amino groups (-NH2) in the polyamine or branching polyamine compound.

[0016] In formula (1) and (G), each Q is independently the same or different, and is a divalent C1-60 hydrocarbon group. In a preferred aspect, Q is a C6-20 arylene, a Ci-20 alkylene, or a C3-8 cycloalkylene. In a more preferred aspect, Q is a C6-20 arylene.

[0017] In formula (1) and (G), each M is independently the same or different, and is -O- , -C(O)-, -OC(O)-, -0C(0)0-, -NHC(O), -(O)CNH-, -S-, -S(O)-, -S(0) ₂ -. In another aspect, M is - O- , -C(O)-, -OC(O)-, -P(R ^a )-, or -P(0)R ^a -. In an aspect, M is -O- , -C(O)-, -OC(O)-, -P(R ^a )-, or -P(0)R ^a - wherein R ^a is a Ci-s alkyl or C6-12 aryl.

[0018] In formula (1) and (G), each D is phenylene. In an aspect, each D is the same or different, and is m-phenylene or p-phenylene.

[0019] Further in formula (1) and (G), each V is independently the same or different, and is a tetravalent C4-40 hydrocarbon group, optionally with 1 to 3 heteroatoms. In an aspect, V is a C6-20 aromatic hydrocarbon group, optionally with 1 to 3 heteroatoms. Exemplary groups include any of those of the formulas (2) wherein W is -0-, -S-, -C(O)-, -SO2-, -SO-, -P(R ^a )(=0)- wherein R ^a is a Ci-s alkyl or C6-12 aryl, - C _y th _y - wherein y is an integer from 1 to 5 or a halogenated derivative thereof (which includes perfluoroalkylene groups), or a group of the formula -O-Z-O- as described in formula (la) and (la') below.

[0020] Also, in formula (1) and (G), each R is independently the same or different, and is a Ci -24 divalent hydrocarbon group. Specifically, each R can be the same or different, and is a divalent organic group, such as a C6-24 aromatic hydrocarbon group or a halogenated derivative thereof, a straight or branched chain C2-20 alkylene group or a halogenated derivative thereof, a C3-8 cycloalkylene group or halogenated derivative thereof, in particular a divalent group of any of formulas (3) wherein Q ¹ is -0-, -S-, -C(O)-, -SO2-, -SO-, -P(R ^a )(=0)- wherein R ^a is a Ci-s alkyl or C6-12 aryl, - C _y th _y - wherein y is an integer from 1 to 5 or a halogenated derivative thereof (which includes perfluoroalkylene groups), or -(C ₆ Hio) _z - wherein z is an integer from 1 to 4. In an aspect R is m- phenylene, p-phenylene, or a diarylene sulfone.

[0021] Still further in formula (1) and (G), each n is independently the same or different, and is 1 to 1,000, preferably 2 to 500, or 3 to 100, provided that the total of all values of n is greater than 4, preferably greater than 10, more preferably greater than 20, or greater than 50, or greater than 100, or greater than 250, or 4 to 50, or 10 to 50, or 20 to 50, or 4 to 100, or 10 to 100, or 20 to 100.

[0022] In certain aspects, the reinforced polyimide composition includes 20 to 70 wt% of the linear polyimide, 5 to 70 wt% of the branched polyimide, and 10 to 45 wt% of reinforcing material, and G is present in an amount 0.1 to 5 mol%. In other aspects, the polyimide composition includes 20 to 50 wt% of the linear polyimide, 10 to 40 wt% of the branched polyimide, and 15 to 45 wt% of reinforcing material, and G is present in an amount 0.2 to 4 mol%.

[0023] In another specific aspect, the branched polyimide of formula (1) or ( ) can be a polyetherimide of formula (la), preferably (la') wherein G, Q, M, D, R, q, m, d, n, p, and t are as defined in formula (1) and (G), and wherein the divalent bonds of the -O-Z-O- group are in the 3,3', 3,4', 4,3', or the 4,4' positions. The group Z in -O-Z-O- of formula (la) and (la') is a divalent organic group, and can be an aromatic Ce-24 monocyclic or polycyclic moiety optionally including 1 to 3 heteroatoms, and optionally substituted with 1 to 6 Ci-s alkyl groups, 1 to 8 halogen atoms, or a combination thereof, provided that the valence of Z is not exceeded. Exemplary groups Z include groups derived from a dihydroxy compound of formula (4) wherein R ^a and R ^b can be the same or different and are a halogen atom or a monovalent Ci- ₆ alkyl group, for example; p' and q' are each independently integers of 0 to 4; c is 0 to 4; and X ^a is a bridging group connecting the hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each Ce arylene group are disposed ortho, meta, or para (preferably para) to each other on the Ce arylene group. The bridging group X ^a can be a single bond, -0-, -S-, -S(O)-, -S(0) ₂ -, -C(O)-, or a Ci-is organic bridging group. The C _MS organic bridging group can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. The Ci-is organic group can be disposed such that the Ce arylene groups connected thereto are each connected to a common alkylidene carbon or to different carbons of the Ci-is organic bridging group. A specific example of a group Z is a divalent group of formula (4a) wherein J is a single bond, -0-, -S-, -C(O)-, -SO ₂ -, -SO-, or -C _y th _y - wherein y is an integer from

1 to 5 or a halogenated derivative thereof (including a perfluoroalkylene group). In a specific aspect Z is a derived from bisphenol A, such that J in formula (4a) is 2,2-isopropylidene. [0024] In an aspect in formulas (1), (G), (la), and (la'), R is m-phenylene or p- phenylene, bis(4,4’-phenylene)sulfone, bis(3,4’-phenylene)sulfone, or bis(3,3’- phenylene)sulfone. In this aspect, Z can be a divalent group of formula (4a). In an alternative aspect, R is m-phenylene or p-phenylene and Z is a divalent group of formula (4a) and J is 2,2- isopropylidene.

[0025] In some aspects, the branched polyimide can be a copolymer, for example a polyetherimide sulfone copolymer comprising structural units of formulas (1), (G), (la), or (la') wherein at least 50 mol% of the R groups are of formula (3) wherein Q ¹ is -SO2- and the remaining R groups are independently p-phenylene or m-phenylene or a combination thereof; and Z is 2,2’-(4-phenylene)isopropylidene. Alternatively, the polyetherimide copolymer optionally comprises additional structural imide units, for example imide units wherein V is of formula (2a) wherein R and V are as described in formula (2a), for example V is wherein W is a single bond, -0-, -S-, - wherein R ^a is a Ci-s alkyl or C6-12 aryl, or -Cythy- wherein y is an integer from 1 to 5 or a halogenated derivative thereof (which includes perfluoroalkylene groups). These additional structural imide units can comprise less than 20 mol% of the total number of units, or 0 to 10 mol% of the total number of units, or 0 to 5 mol% of the total number of units, or 0 to 2 mol% of the total number of units. In some aspects, no additional imide units are present in the branched polyimide other than polyetherimide units.

[0026] The branched polyimide (which as indicated above includes polyimides (1) and (G) and the polyetherimides (la) and (la')), can be prepared by methods known in the art, including a polycondensation or ether-forming polymerization. In any process, the appropriate amount of a polyamine of formula (5), preferably of formula (5') is introduced during manufacture of the branched polyimide as described in further detail below. In formula (5) and (5'), G, Q, M, D, q, m, d, p, and t are defined as described in formulas (1), (G), (la), and (la').

[0027] Exemplary polyamines (5) and (5') can include any of formulas (5a)-(5t):

wherein, in formula (5f), Z is a divalent C1-60 hydrocarbon group, or a Ce- _AO aromatic hydrocarbon group, a C2-20 aliphatic group, or a C4-8 cycloaliphatic group. In a particular aspect, the polyamine is of the formulas (5b), (5k), (5r), (5s), or (5t), preferably 5(k).

[0028] Methods for the synthesis of the polyamines are known in the art. An exemplary method for the synthesis of the polyamine of formulas (5) and (5') uses a two-step sequence. For example, in the first step, a nucleophilic aromatic substitution of a halogenated aromatic nitro compound (e.g., l-chloro-4-nitrobenzene) with a polyphenol (e.g., l,l,l-tris(4-hydroxyphenyl) ethane) that is converted to a polyphenoxide in-situ, providing a sufficiently nucleophilic oxygen to displace the activated halide. A polar aprotic solvent (e.g., dimethylacetamide) can promote the substitution reaction to afford a poly(nitrophenyl) compound (e.g., l,l,l-tris((p- nitrophenoxy)phenyl) ethane). The second step is a reduction of the poly(nitrophenyl) compound to the polyamine of formula (5) using, for example, a palladium catalyst with a reducing agent, an iron-based catalyst, vasicine, zinc, samarium, and hydrazine.

[0029] The branched polyimide can be prepared by polycondensation, which includes an imidization of a dianhydride of formula (6) or formula (6a) or a chemical equivalent thereof, with a combination of an organic diamine of formula (7)

H2N-R-NH2 (7) and the polyamine of formula (5), preferably of formula (5'), wherein V, Z, R, G, Q, M, D, q, m, d, p, and t are defined as described in formulas (1), (G), (la), and (la'). The polyamine (5), preferably (5') can be present in the reaction in an amount of 0.1 to 20 mol%, or 0.5 to 10 mol%, or 1.0 to 5 mol%, or 1.5 to 4 mol%, based on the total moles of the organic diamine (7) and the polyamine (5). It is to be understood that “the total moles of the organic diamine (7) and the polyamine (5)” refers to the total of the moles of amine functionality (also referred to herein as “reactive amino groups”) per mole of organic diamine and per mole of polyamine. Accordingly, the total molar amount of amine functionality of an organic diamine and a polyamine used to prepare the polyimide is defined as [2 x diamine moles] + [t x polyamine moles], wherein t is the number of reactive amino groups in the polyamine.

[0030] It is to be understood that the amount of the branching polyamine (5) used in the synthesis of the branched polyimide is equal to the mole percent of the branching group G in the resulting branched polyimide. Accordingly, the branched polyimide is described herein as having a “branching level” of 0.1 to 20 mol%, or 0.5 to 10 mol%, or 1.0 to 5 mol%, or 1.5 to 4 mol% when G is present in the branched polyimide an amount of 0.1 to 20 mol%, or 0.5 to 10 mol%, or 1.0 to 5 mol%, or 1.5 to 4 mol%, based on 100 mol% of total molar amount of amine functionality of an organic diamine and a polyamine used to prepare the polyimide.

[0031] Exemplary dianhydrides (6) or (6a) include 3,3-bis[4-(3,4- dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl ether dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride; 4,4'-bis(3,4- dicarboxyphenoxy)benzophenone dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride; 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(2,3- dicarboxyphenoxy)diphenyl ether dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)diphenyl sulfide dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)benzophenone dianhydride; 4,4'-bis(2,3- dicarboxyphenoxy)diphenyl sulfone dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4- dicarboxyphenoxy)diphenyl-2, 2-propane dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4- dicarboxyphenoxy)diphenyl ether dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4- dicarboxyphenoxy)diphenyl sulfide dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4- dicarboxyphenoxy)benzophenone dianhydride; and, 4-(2,3-dicarboxyphenoxy)-4'-(3,4- dicarboxyphenoxy)diphenyl sulfone dianhydride, as well as various combinations thereof.

[0032] Specific examples of organic diamines (7) include hexamethylenediamine, polymethylated 1,6-n-hexanediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, 1,12-dodecanediamine, 1,18- octadecanediamine, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 4- methylnonamethylenediamine, 5-methylnonamethylenediamine, 2,5-dimethyl- hexamethylenediamine, 2,5-dimethylheptamethylenediamine, 2, 2-dimethyl-propylenediamine, N-methyl-bis(3-aminopropyl)amine, 3-methoxyhexamethylenediamine, 1 ,2-bis(3- aminopropoxy)ethane, bis(3-aminopropyl) sulfide, 1,4-cyclohexanediamine, bis-(4- aminocyclohexyl) methane, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6- diaminotoluene, m-xylylenediamine, p-xylylenediamine, 2-methyl-4, 6-diethyl- 1,3-phenylene- diamine, 5-methyl-4, 6-diethyl- 1,3-phenylene-diamine, benzidine, 3,3’-dimethylbenzidine, 3,3’- dimethoxybenzidine, 1,5-diaminonaphthalene, bis(4-aminophenyl) methane, bis(2-chloro-4- amino-3,5-diethylphenyl) methane, bis(4-aminophenyl) propane, 2,4-bis(p-amino-t-butyl) toluene, bis(p-amino-t-butylphenyl) ether, bis(p-methyl-o-amino-phenyl) benzene, bis(p-methyl- o-aminopentyl) benzene, 1, 3-diamino-4-isopropylbenzene, bis(4-aminophenyl) sulfide, bis-(4- aminophenyl) sulfone (also known as 4,4'-diaminodiphenyl sulfone (DDS)), and bis(4- aminophenyl) ether. Any regioisomer of the foregoing compounds can be used. Combinations of these compounds can also be used. In some aspects the organic diamine is m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl sulfone, or a combination thereof.

[0033] In some aspects, the poly condensation is conducted in the presence of an endcapping agent. Exemplary endcapping agents include, but are not limited to phthalic anhydride, aniline, Ci-is linear, branched or cyclic aliphatic monoamines, monofunctional aromatic amines of the formula (8a), and an aliphatic- or aryl-substituted phthalic anhydride of the formula (8b) wherein R is a Ci-is linear, branched, or cyclic aliphatic alkyl or alkenyl, or a Ce-24 monocyclic aryl. In an aspect, the endcapping agent is not 4-phenylethynylphthalic anhydride. The endcapping agent can be added at any time, e.g., to the polyamine (5), the organic diamine (7), the dianhydride (6), or a combination thereof, before or after the polycondensation reaction has started. In some aspects, the endcapping agents are mixed with or dissolved into reactants having the similar functionality. For example, monoamine endcapping agents can be mixed with or dissolved into diamines, and monoanhydride can be mixed with or dissolved into dianhydrides.

[0034] If an amine-containing endcapping agent is used, the amount can be more than 0 to 10 mol% based on the total amount of dianhydride (6) or (6a). If an anhydride-containing endcapping agent is used, the amount can be in the range of more than 0 to 20 mol%, or 1 to 10 mol% based on the amount of the polyamine (5), preferably (5'), and organic diamine (7) combined. In general, due to the presence of the polyamines, an anhydride-containing endcapping agent is used to decrease the number of amine end groups in the branched polyimide and polyetherimide. For example, anhydride-containing endcapping agent can be combined with dianhydride (6) or (6a). Where an anhydride-containing endcapping agent is used, in order to achieve maximum molecular weight, the quantity of amine functionality ([2 x diamine moles] + [t x polyamine, moles wherein t is the number of reactive amino groups]) = moles of anhydride functionality ([2 x dianhydride moles + moles of anhydride in the endcapping agent]). As described above, the stoichiometry condition of the polymerization reaction mixture can be analyzed, and the stoichiometry corrected if needed to provide a stoichiometry within + 0.2 mol% of a stoichiometry of 1 : 1.

[0035] A catalyst can be present during imidization. Exemplary catalysts include sodium aryl phosphinates, guanidinium salts, pyridinium salts, imidazolium salts, tetra(C7-24 arylalkylene) ammonium salts, dialkyl heterocyclo aliphatic ammonium salts, bis-alkyl quaternary ammonium salts, (C7-24 arylalkylene)(Ci-i6 alkyl) phosphonium salts, (C6-24 aryl)(Ci- 16 alkyl) phosphonium salts, phosphazenium salts, and combinations thereof. The anionic component of the salt is not particularly limited, and can be, for example, chloride, bromide, iodide, sulfate, phosphate, acetate, maculate, tosylate, and the like. A combination of different anions can be used. A catalytically active amount of the catalyst can be determined by one of skill in the art without undue experimentation, and can be, for example, more than 0 to 5 mol% percent, or 0.01 to 2 mol%, or 0.1 to 1.5 mol%, or 0.2 to 1.0 mol% based on the moles of polyamine (5) and organic diamine (7).

[0036] Conditions effective to provide the branched polyimides are generally known. Polymerization is generally carried out in a solvent, for example relatively non-polar solvents with a boiling point above 100°C, or above 150° C, for example o-dichlorobenzene, dichlorotoluene, 1,2,4-trichlorobenzene, diphenyl sulfone, or a monoalkoxybenzene such as anisole, veratrole, diphenylether, or phenetole. Ortho-dichlorobenzene and anisole can be particularly mentioned. The polymerization is generally at least 110°C, or 150 to 275°C, or 175 to 225°C for solution polymerization. At temperatures below 110°C, reaction rates may be too slow for economical operation. Atmospheric or super-atmospheric pressures can be used, for example up to 5 atmospheres, to facilitate the use of elevated temperatures without causing solvent to be lost by evaporation. Effective times depend on the reactants and reaction conditions, and can be 0.5 hours to 3 days, for example, generally for 0.5 to 72 hours, preferably 1 to 30 hours, or 2 to 20 hours. Advantageously, the reaction is complete 20 hours or less, preferably 10 hours or less, more preferably 3 hours or less.

[0037] It has been found that improved compositions can be obtained by pre-dissolving the polyamine (5), preferably (5'), and the organic diamine (7) before adding the dianhydride (6) or (6a), or before adding the diamine/polyamine to the dianhydride. The catalyst can be added any time during the reaction between the polyamine (5), preferably (5'), and organic diamine (7), and the dianhydride (6) or (6a) continuously or in portions during the course of the reaction. In some aspects, the catalyst is added after pre-dissolution the polyamine (5), preferably (5'), and organic diamine (7), with the dianhydride (6) or (6a).

[0038] A molar ratio of dianhydride (6) or (6a) to a combination of polyamine (5), preferably (5'), and organic diamine (7) of 0.9:1 to 1.1:1, or 1:1 can be used. While other ratios can be used, a slight excess of dianhydride or diamine may be desirable. A proper stoichiometric balance between the dianhydride and combination of polyamine (5), preferably (5'), and organic diamine (7) is maintained to allow for the production of the desired molecular weight of the polymer, or prevent the formation of polymer with significant amounts of amine end groups. Accordingly, in an aspect, imidization proceeds via forming an initial reaction mixture having a targeted initial molar ratio of dianhydride (6) or (6a) to a combination of polyamine (5), preferably (5'), and organic diamine (7); heating the reaction mixture to a temperature of at least 100°C to initiate polymerization; analyzing the molar ratio of the heated reaction mixture to determine the actual initial molar ratio of dianhydride (6) or (6a) to polyamine (5), preferably (5'), and organic diamine (7), using, e.g., acid-based titration method, an infrared spectroscopy technique, or proton nuclear magnetic resonance; and, if necessary, adding dianhydride (6) or (6a), or polyamine (5), preferably (5'), or organic diamine (7) to the analyzed reaction mixture to adjust the molar ratio of dianhydride (6) or (6a) to polyamine (5), preferably (5'), and organic diamine (7) to 0.9:1 to 1.1:1.

[0039] In other aspects, the branched polyimide is a branched polyetherimide, and can be synthesized by an ether-forming polymerization, which proceeds via imidization by reaction of the polyamine (5) and the diamine (7) with an anhydride of formula (9) wherein X is a nitro group or halogen, to provide intermediate bis(phthalimide)s of the formulas (10a) and (10b) wherein G, Q, M, q, m, p, and t are as described in formula (1) and (la) and X is as described in formula (9). The polyamine (5), preferably (5'), can be present in the reaction in an amount of 0.1 to 20 mol%, or 0.5 to 10 mol%, but preferably 1.0 to 5 mol%, or 1.5 to 4 mol% to achieve increased branching. An optional catalyst or optional end capping agent as described above can be present during imidization.

[0040] The bis(phthalimide)s (10a) and (10b) can be reacted with an alkali metal salt of a dihydroxy aromatic compound of formula (11)

AMO-Z-OAM (11) wherein AM is an alkali metal and Z is as defined above, to provide the branched polyetherimide. Polymerization conditions effective to provide the branched polyimide are generally known and can be conducted in a solvent as described above. This polymerization can also be conducted in the melt, for example at 250 to 350°C, where a solvent is typically not present.

[0041] The linear polyimide is generally an unbranched polyimide that comprises more than 1, for example 5 to 1000, or 5 to 500, or 10 to 100, structural units of formula (12) o o

A A Y OY o ^r (12) wherein V and R are as described in formula (1) and (G). In some aspects, the linear polyimide is a polyetherimide that is generally an unbranched polyetherimide that comprises more than 1, for example 5 to 1000, or 5 to 500, or 10 to 100, structural units of formula (13) wherein Z and R are as described in formula (la) and (la'). In particular aspects, the linear polyimide has structural units of formula (12) and the branched polyimide is of formula (1) or (G), wherein V and/or R are the same in both the linear polyimide and the branched polyimide. In another particular aspect, the linear polyimide is a polyetherimide having structural units of formula (13) and the branched polyimide is a polyetherimide of formula (la) or (la’), wherein Z and/or R are the same in both the linear polyimide and the branched polyimide.

[0042] In some aspects, the reinforced polyimide composition can be prepared by melt processing the linear polyimide and the branched polyimide using any suitable method. For example, powdered polyimides, and other optional components are first blended, optionally with any fillers, in a high speed mixer or by hand mixing. The blend is then fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the components can be incorporated into the composition by feeding it directly into the extruder at the throat or downstream through a sidestuffer, or by being compounded into a masterbatch with a desired polymer and fed into the extruder. The extruder is typically operated at a temperature higher than that necessary to cause the composition to flow. The extmdate can be immediately quenched in a water bath and pelletized. The pellets so prepared can be one-fourth inch long or less as desired. Such pellets can be used for subsequent molding, shaping, or forming.

[0043] In some aspects, the reinforced polyimide composition can have a total branched mole percent of less than 1.0, preferably less than 0.9, more preferably less than 0.5, wherein the total branched mole percent (TBMP) is determined according to Equation 1:

Equation 1

TBMP = [mol% branching of branched PEI] x [amount of branched PEI in the composition] wherein “mol% branching of branched PEI” refers to the mole percent of branching polyamine used to prepare the branched PEI, which also is equal to the mole percent of the branching group G in the branched polyimide; and wherein “amount of branched PEI in the composition” refers to the amount by weight of the branched PEI in the composition based on 100 wt% total of the composition. Without being bound to theory, a reinforced polyimide composition having a TBMP of less than 1.0 can improve impact resistance.

[0044] In addition to the linear polyimide and the branched polyimide, the polyimide composition further includes a reinforcing material.

[0045] Reinforcing materials can include hollow or solid glass spheres, carbon fiberglass spheres, whiskers of silicon carbide or silicon nitride, continuous or chopped carbon fibers, continuous or chopped glass fibers, flaked glass, milled glass, flaked silicon carbide or nitride, flaked aluminum diboride, flaked aluminum, steel flakes, as well as combinations comprising at least one of the foregoing reinforcing materials. The reinforcing materials can be coated with a metallic layer to improve conductivity, or surface treated with silanes to improve adhesion and dispersion within the polymer matrix. In an aspect, the reinforcing material can be hollow or solid glass spheres, continuous or chopped carbon fibers, continuous or chopped glass fibers, flaked glass, milled glass, continuous or chopped elliptical or flat glass, or a combination thereof. For example, the reinforcing filler can be glass fiber, carbon fiber, or a combination thereof.

[0046] Exemplary glass fibers can be formed from any type of known fiberizable glass composition, and include, for example, those prepared from fiberizable glass compositions commonly known as “E-glass,” “C-glass,” “D-glass,” “R-glass,” “S-glass,” as well as E-glass derivatives that are fluorine-free and/or boron-free. Commercially produced glass fibers generally have nominal filament diameters of 4.0 to 35.0 micrometers (pm), and most produced E-glass fibers can have a nominal filament diameter of 9.0 to 30.0 micrometers. For example, glass fibers can have a diameter of 9 to 20 pm, specifically 10 to 15 pm. The filaments can be made by standard processes, for example, by steam or air blowing, flame blowing and mechanical pulling. The filaments for polymer reinforcement can be made by mechanical pulling. A fiber having a non-round cross section can also be used. The glass fibers can be sized or unsized. In a specific embodiment, the reinforcing filler can be an E-glass fiber having a diameter of 5 to 20 micrometers, specifically 9 to 20 pm, and more specifically 10 to 15 pm. The glass fibers can have various cross-sectional shapes, for example, round, trapezoidal, rectangular, square, crescent, bilobal, trilobal, and hexagonal. In one embodiment, the glass can be soda free. Fibrous glass fibers comprising lime-alumino-borosilicate glass, known as “E” glass, can be especially useful. Glass fibers, when present, can increase the flexural modulus and strength of the polyetherimide compositions. The glass fibers can be used in the form of chopped strands, having lengths of 3 mm (about ½ inch ) to 13 mm (about ½ inch ) In some aspects, rovings can also be used. The glass fiber length in molded articles prepared from compositions comprising the glass fibers can be shorter than the above mentioned lengths, presumably due to fiber fragmentation during compounding of the composition. For example, the length of the glass fibers in a molded article can be less than 2 millimeters (mm).

[0047] The fibers can optionally be treated with various coupling agents to improve adhesion to the polymeric matrix. Examples of coupling agents can include alkoxy silanes and alkoxy zirconates, amino-, epoxy-, amide- and mercapto-functionalized silanes, and organometallic coupling agents, including, for example, titanium- or zirconium-containing organometallic compounds.

[0048] The reinforcing material is present in the polyimide composition in an amount from 5 to 50 wt%, preferably 10 to 45 wt%, more preferably 15 to 45 wt%, even more preferably 15 to 30 wt%, based on the total weight of the polyimide composition. [0049] It is also possible to combine the reinforced polyimide composition with an additional polymer that is different from the linear polyimide or the branched polyimide to provide a polymer composition. Such polymer compositions can include 1 to 99 wt% of the reinforced polyimide composition and 1 to 99 wt% of the additional polymer, 10 to 90% of the reinforced polyimide composition and 10 to 90 wt% of the additional polymer, or 25 to 75% of the reinforced polyimide composition and 25 to 75 wt% of the additional polymer.

[0050] The additional polymer is a thermoplastic. Illustrative examples of the additional polymer include a polyacetal, poly(Ci- ₆ alkyl)acrylate, polyacrylamide, polyacrylonitrile, polyamide, polyamideimide, polyanhydride, polyarylene ether, polyarylene ether ketone, polyarylene ketone, polyarylene sulfide, polysulfone, polybenzothiazole, polybenzoxazole, polybenzimidazole, polycarbonate, polyester, poly(Ci- ₆ alkyl)methacrylate, polymethacrylamide, cyclic olefin polymer, polyolefin, polyoxadiazole, polyoxymethylene, polyphthalide, polysilazane, polysiloxane, polystyrene, polysulfide, polysulfonamide, polysulfonate, polythioester, polytriazine, polyurea, polyurethane, vinyl polymer, or a combination comprising at least one of the foregoing.

[0051] The reinforced polyimide composition or the polymer composition can include various additives ordinarily incorporated into compositions of this type, with the proviso that any additive is selected so as to not significantly adversely affect the desired properties of the reinforced polyimide composition. Exemplary additives include antioxidants, impact modifiers, thermal stabilizers, light stabilizers, ultraviolet light (UV) absorbing additives, quenchers, plasticizers, lubricants, mold release agents, antistatic agents, visual effect additives such as dyes, pigments, and light effect additives, flame resistances, anti-drip agents, and radiation stabilizers. Combinations of additives can be used. The foregoing additives can be present individually in an amount from 0.005 to 10 wt%, or combined in an amount from 0.005 to 20 wt%, preferably 0.01 to 10 wt%, based on the total weight of the composition.

[0052] The reinforced polyimide compositions as well as any comparative polyimide reference compositions can be formed into pellets or other forms (herein referred to as “samples”) using extruding techniques in the art, for example, using a twin-screw, vacuum vented, 30 mm Wemer Pfleiderer twin screw extruder with six barrel sections. Extrusion can be performed at select barrel temperatures in one or more extruder zones. Extrusion can be run with vacuum venting, and the use of a twin-screw extruder can provide enough distributive and dispersive mixing to produce good mixing between the chemical and physical components of the reinforced polyimide compositions. The melt processed compositions can exit the extruder through small exit holes in a die, the resulting strands can be cooled, and the strands can then be milled to form pellets. The extruded pellets can be molded into shapes suitable for applicable mechanical testing.

[0053] The measured mechanical and physical properties of samples prepared from the reinforced polyimide composition can be compared to a reference sample. The reference sample is derived from a reference polyimide composition that includes the linear polyimide, a same amount of the reinforcing material as the reinforced polyimide sample, and does not comprise the branched polyimide. The reference composition is prepared with linear polyimide, i.e., in the absence of any branched polyimide, and the same type and weight percentage of reinforcing material. A reference composition will also include an additional amount of the linear polyimide to correspond to an amount of branched polyimide that is absent from the reference composition.

[0054] In an aspect, the reinforced polyimide composition has a melt flow rate of 19 to 50 g/10 min, or 25 to 50 g/10 min, or 30 to 50 g/10 min, or 20 to 40 g/10 min, or 20 to 30 g/10 min, or 30 to 40 g/10 min, each as measured at 337 °C at a shear load of 6.7 kg, in accordance with ASTM 1238.

[0055] In an aspect, the reinforced polyimide composition has an apparent viscosity that is less than an apparent viscosity of a reference composition as measured at 360 °C at a shear rate of 640 inverse seconds (s ¹ ) in accordance with ISO 11443.

[0056] In an aspect, the reinforced polyimide composition includes reinforcing material that is in the form of a fiber, and the reinforcing material is present in an amount from 15 to 45 wt%. The fiber reinforced polyimide composition has at least one of the following: a melt flow rate that is greater than a melt flow rate of a reference composition, as measured at 337 °C at a shear load of 6.7 kg, in accordance with ASTM 1238; or an apparent viscosity of less than 1200 Pascal second (Pa-s) and greater than 500 Pa-s, and the apparent viscosity is less than an apparent viscosity of a reference composition, as measured at 360 °C at a shear rate of 640 s ¹ in accordance with ISO 11443; or an apparent viscosity of less than 400 Pa- s and greater than 180 Pa-s, and the apparent viscosity is less than an apparent viscosity of a reference composition, as measured at 360 °C at a shear rate of 5000 s ¹ in accordance with ISO 11443.

[0057] In an aspect, the reinforced polyimide composition with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, has an apparent viscosity of less than 820 Pa-s, preferably less than 790 Pa- s, more preferably less than 760 Pa- s as measured at 360°C at a shear rate of 640 s ¹ in accordance with ISO 11443. In particular aspects, the reinforced polyimide composition has an apparent viscosity of 400 to 820 Pa- s, or 500 to 820 Pa- s, or 600 to 820 Pa- s, or 550 to 820 Pa-s, or 550 to 790 Pa-s, or 550 to 760 Pa-s, or 600 to 820 Pa-s, or 600 to 790 Pa- s, or 600 to 760 Pa- s, or 650 to 820 Pa- s, or 650 to 790 Pa- s, or 650 to 760 Pa- s, each as measured at 360 °C at a shear rate of 640 s ¹ in accordance with ISO 11443. In a particular aspect, the reinforcing material is in the form of cut or endless fibers, e.g., glass fibers. [0058] In an aspect, the reinforced polyimide composition has an apparent viscosity that is less than an apparent viscosity of a reference composition as measured at 360 °C at a shear rate of 5000 s ¹ in accordance with ISO 11443. In an aspect, the reinforced polyimide composition with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, has an apparent viscosity of less than 300 Pa-s, preferably less than 275 Pa-s, more preferably less than 250 Pa- s, as measured at 360 °C at a shear rate of 5000 s ¹ in accordance with ISO 11443. In particular aspects, the reinforced polyimide composition has an apparent viscosity of 150 to 300 Pa-s, or 150 to 275 Pa-s, or 150 to 250 Pa-s, or 175 to 300 Pa-s, or 175 to 275 Pa-s, or 175 to 250 Pa- s, or 200 to 300 Pa- s, or 200 to 275 Pa- s, or 200 to 250 Pa- s, as measured at 360 °C at a shear rate of 5000 s ¹ in accordance with ISO 11443. In a particular aspect, the reinforcing material is in the form of cut or endless fibers, e.g., glass fibers.

[0059] In an aspect, the reinforced polyimide composition has an apparent viscosity that is less than an apparent viscosity of a reference composition as measured at 360 °C at a shear rate of 640 s ¹ in accordance with ISO 11443. In an aspect, the reinforced polyimide composition with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, has an apparent viscosity of less than 1200 Pa-s, preferably less than 1100 Pa-s, more preferably less than 1000 Pa-s, as measured at 360°C at a shear rate of 640 s ¹ in accordance with ISO 11443. In particular aspects, the reinforced polyimide composition has an apparent viscosity of 800 to 1150 Pa- s, or 900 to 1150 Pa- s, or 1000 to 1150 Pa- s, or 800 to 1000 Pa- s, or 900 to 1000 Pa- s, as measured at 360 °C at a shear rate of 640 s ¹ in accordance with ISO 11443. In a particular aspect, the reinforcing material is in the form of cut or endless fiber, e.g., glass fibers.

[0060] The reinforced polyimide composition can have a viscosity change of less than 40%, preferably less than 32%, more preferably less than 26% after 1,800 seconds (s) at a temperature of 380 °C at a shear rate of 640 s ¹ . In certain aspects, the polyimide composition has a viscosity change of 18 to 40%, or 22 to 40%, or 24 to 40%, or 24 to 36%, 24 to 34%, or 26 to 34%, or 26 to 32%, after 1,800 s at a temperature of 380 °C at a shear rate of 640 s ¹ .

[0061] Reinforced polyimide samples can have a notched Izod impact strength that is greater than a notched Izod impact strength of a reference sample, as measured at 23 °C and 6.78 Newton meter (N-m, or 5 pound per foot) of pendulum force in accordance with ASTM D256.

In an aspect, a reinforced polyimide sample with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, can have a notched Izod impact strength of at least 40 Joules per meter (J/m), preferably at least 55 J/m, more preferably at least 60 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a notched Izod impact strength of 50 to 75 J/m, or 55 to 75 J/m, or 60 to 75 J/m, or 50 to 70 J/m, or 50 to 65 J/m, or 60 to 65 J/m, or 50 to 60 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0062] In an aspect, a reinforced polyimide sample with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, can have a notched Izod impact strength of at least 60 J/m, preferably at least 65 J/m, more preferably at least 70 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a notched Izod impact strength of 60 to 95 J/m, or 65 to 95 J/m, or 70 to 95 J/m, or 65 to 85 J/m, or 70 to 85 J/m, or 75 to 85 J/m, or 70 to 80 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0063] A reinforced polyimide sample with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, can have a unnotched Izod impact strength of at least 375 J/m, preferably at least 425 J/m, more preferably at least 500 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a unnotched Izod impact strength of 375 to 650 J/m, or 425 to 650 J/m, or 500 to 650 J/m, or 425 to 650 J/m, or 425 to 600 J/m, or 425 to 500 J/m, 500 to 650 J/m, or 500 to 600 J/m, as measured at 23 °C and 6.78 N-m, in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0064] In an aspect, a reinforced polyimide sample with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, can have an unnotched Izod impact strength of at least 60 J/m, preferably at least 65 J/m, more preferably at least 70 J/m, as measured at 23 °C and 6.78 N-m in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a unnotched Izod impact strength of 375 to 650 J/m, or 425 to 650 J/m, or 500 to 650 J/m, or 425 to 650 J/m, or 425 to 600 J/m, or 425 to 500 J/m, 500 to 650 J/m, or 500 to 600 J/m, as measured at 23 °C and 6.78 N-m, in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0065] In certain aspects, a reinforced polyimide sample with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, can have a reverse notched Izod impact strength of at least 250 J/m, preferably at least 300 J/m, more preferably at least 350 J/m, as measured at 23°C and 6.78 N-m of pendulum force, in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a reverse notched Izod impact strength of 250 to 450 J/m, or 300 to 450 J/m, or 350 to 450 J/m, or 300 to 400 J/m, or 325 to 400 J/m, as measured at 23 °C and 6.78 N-m, in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0066] In certain aspects, a reinforced polyimide sample with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, can have a reverse notched Izod impact strength of at least 250 J/m, preferably at least 300 J/m, more preferably at least 350 J/m, as measured at 23 °C and 6.78 N-m of pendulum force, in accordance with ASTM D256. In particular aspects, a reinforced polyimide sample can have a reverse notched Izod impact strength of 200 to 400 J/m, or 250 to 300 J/m, or 250 to 400 J/m, or 300 to 400 J/m, or 325 to 400 J/m, as measured at 23 °C and 6.78 N-m, in accordance with ASTM D256. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0067] In an aspect, a reinforced polyimide sample can have a flexural modulus, a tensile modulus, or both, which is greater than the flexural modulus or a tensile modulus of a reference sample. In one aspect, the reinforced polyimide sample has at least one of the following: a flexural modulus that is 4% to 25% greater than a reference sample, as measured at 3.2 mm/min at 23 °C in accordance with ASTM D790; or a tensile modulus that is 8% to 45% greater than a reference sample, as measured at 5 mm/min at 23 °C in accordance with ASTM D638. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0068] In an aspect, a reinforced polyimide sample with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, can have a flexural modulus of at least 5400 MPa or 5600 MPa, preferably at least 5700 MPa or 5850 MPa, most preferably at least 6000 MPa or 6200 MPa, as measured at 3.2 mm/min at 23 °C in accordance with ASTM D790. In particular aspects, a reinforced polyimide sample can have a flexural modulus of 5600 to 6700 MPa, or 5800 to 6700 MPa, or 6000 to 6700 MPa, or 5700 to 6500 MPa, or 6000 to 6500 MPa, or 6100 to 6500 MPa, or 6250 to 6500 MPa, as measured at 3.2 mm/min at 23 °C in accordance with ASTM D790. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0069] In an aspect, a reinforced polyimide sample with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, can have a flexural modulus of at least 9500 MPa or 10,800 MPa, preferably at least 11,200 MPa or 11,800 MPa, most preferably at least 12,000 MPa is measured at 3.2 mm/min at 23 °C in accordance with ASTM D790. In particular aspects, a reinforced polyimide sample can have a flexural modulus of 11,000 to 13,800 MPa, or 11,800 to 13,800 MPa, or 11,800 to 13,200 MPa, or 12,000 to 13,800 MPa, or 12,000 to 13,000 MPa, or 12,200 to 13,000 MPa. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0070] In an aspect, a reinforced polyimide sample with a reinforcing material content of 5 to 25 wt%, or 15 to 25 wt%, can have a tensile modulus of at least 5400 MPa or 5600 MPa, preferably at least 5700 MPa or 5850 MPa, most preferably at least 6000 MPa or 6200 MPa, as measured at 5 mm/min at 23 °C in accordance with ASTM D638. In particular aspects, a reinforced polyimide sample can have a tensile modulus of 5500 to 6700 MPa, or 5700 to 6700 MPa, or 6000 to 6700 MPa, or 5800 to 6500 MPa, or 6000 to 6500 MPa, or 6000 to 6350 MPa. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers

[0071] In an aspect, a reinforced polyimide sample with a reinforcing material content of 25 to 50 wt%, or 35 to 45 wt%, can have a tensile modulus of at least 9500 MPa or 10,800 MPa, preferably at least 11,400 MPa or 11,800 MPa, most preferably at least 12,100 MPa, as measured at 5 mm/min at 23 °C in accordance with ASTM D638. In particular aspects, a reinforced polyimide sample can have a tensile modulus of 9500 to 13,500 MPa, or 11,000 to 13,500 MPa, or 11,800 to 13,500 MPa, or 11,800 to 13,200 MPa, or 12,000 to 13,000 MPa, or 12,200 to 13,000 MPa. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0072] Quite surprisingly is a finding that the glass transition temperature (T _g ) of the reinforced polyimide composition is within plus-minus two percent (± 2%) of a corresponding reference composition that does not include the branched polyimide. The reinforced polyimide composition can have a glass transition temperature (T _g ) that is greater than 100°C, preferably greater than 200°C, more preferably greater than 210°C, even more preferably greater than 215°C. In particular aspects, the polyimide composition has a T _g of 100 to 395°C, or 150 to 395°C, or 175 to 395°C, or 190 to 395°C, or 200 to 395°C, or 210 to 385°C, or 215 to 385°C, or 200 to 375°C, or 210 to 375°C, or 215 to 375°C, or 200 to 365°C, or 210 to 365°C, or 215 to 365°C, or 200 to 350°C, or 210 to 350°C, or 215 to 350°C, or 200 to 325°C, or 210 to 325°C, or 215 to 325°C, or 200 to 315°C, or 210 to 315°C, or 215 to 315°C, or 200 to 305°C, or 210 to 305°C, or 215 to 305°C, or 200 to 295°C, or 210 to 295°C, or 215 to 295°C, or 200 to 285°C, or 210 to 285°C, or 215 to 285°C, or 200 to 275°C, or 210 to 275°C, or 215 to 275°C, or 200 to 260°C, or 210 to 260°C, or 215 to 260°C, or 200 to 250°C, or 200 to 245°C, or 200 to 240°C, or 200 to 235°C, or 200 to 230°C, or 200 to 225°C, or 200 to 220°C, or 210 to 250°C, or 210 to 245°C, or 210 to 240°C, or 210 to 235°C, or 210 to 230°C, or 210 to 225°C, or 210 to 220°C, or 215 to 250°C, or 215 to 245°C, or 215 to 240°C, or 215 to 235°C, or 215 to 230°C, or 215 to 225°C, or 220 to 250°C, or 220 to 250°C, or 220 to 245°C, or 220 to 240°C, or 220 to 235°C, or 220 to 230°C. In a particular aspect, the reinforcing material in the reinforced polyimide composition is in the form of cut or endless fibers, e.g., glass fibers.

[0073] A reinforced polyimide sample can have a heat deflection temperature (HDT) at 0.455 MPa and 3.2 mm that is very similar i.e., within plus-minus two percent, of a corresponding reference sample. In a particular aspect, the reinforcing material in the reinforced polyimide sample is in the form of cut or endless fibers, e.g., glass fibers.

[0074] In one aspect, a polyimide composition includes fibers of silica or non-silica glass, fibers of carbon, or a combination of fibers thereof, and the fibers are present from 15 to 45 wt%, can have one or more thermal properties within ± 2% to that of a reference composition that includes the same linear polyimide, and the same fibers and amount of fibers, as the reinforced polyimide composition. The thermal properties of the reinforced polyimide composition is at least one of: a glass transition temperature from 200 °C to 230 °C as measured with differential scanning calorimetry in accordance with D3418 ASTM; a Vicat B120 softening temperature from 200 °C to 230 °C as measured at 50 N and 50 °C/hour in accordance with ISO 306; or a heat deflection temperature from 195 to 215 °C as measured at 1.82 MPa and 3.2 mm in accordance with ASTM D648.

[0075] In one aspect, a reinforced polyimide composition includes fibers of silica or non silica glass, fibers of carbon, or a combination of fibers thereof, and the fibers are present from 15 to 45 wt%. The polyimide composition has at least one of the following flow properties: a melt flow rate that is greater than a melt flow rate of a reference composition; or an apparent viscosity of less than 1200 Pa-s and greater than 500 Pa-s, and the apparent viscosity is less than an apparent viscosity of the reference composition; and an apparent viscosity of less than 400 Pa-s and greater than 180 Pa-s, and the apparent viscosity is less than an apparent viscosity of the reference composition.

[0076] In one aspect, a polyimide composition that includes fibers of silica or non-silica glass, fibers of carbon, or a combination of fibers thereof, and the fibers are present from 15 to 45 wt%, is used to provide a reinforced polyimide sample. The reinforced polyimide sample having at least one of the following: a notched Izod impact strength of 55 to 95 J/m, and the notched Izod impact strength is greater than a notched Izod impact strength of a reference sample; and a reverse notched Izod impact strength of 250 to 440 J/m, and the notched Izod impact strength is greater than an notched Izod impact strength of the reference sample; or an unnotched Izod impact strength of 360 to 610 J/m, and the unnotched Izod impact strength is greater than an unnotched Izod impact strength of the reference sample.

[0077] The linear polyimide can have a weight average molecular weight (M _w ) of 28,000 to 60,000 grams per mole (g/mol), preferably 30,000 to 50,000 g/mol, more preferably 32,000 to 45,000 g/mol, as determined by size exclusion chromatography (SEC) using triple point detection. In some aspects, the linear polyimide has a M _w of 29,000 to 55,000 g/mol, or 29,000 to 52,000 g/mol 29,000 to 48,000 g/mol, or 30,000 to 47,000 g/mol, or 30,000 to 45,000 g/mol, or 31,000 to 45,000 g/mol, or 32,000 to 43,000 g/mol, 33,000 to 41,000 g/mol, or 34,000 to 40,000 g/mol, or 28,000 to 40,000 g/mol, or 29,000 to 39,000 g/mol, or 28,000 to 38,000 g/mol, or 28,000 to 35,000 g/mol, or 30,000 to 40,000 g/mol, or 30,000 to 38,000 g/mol, as determined by triple point detection.

[0078] The branched polyimide can have a M _w of 28,000 to 60,000 g/mol, preferably 30,000 to 54,000 g/mol, more preferably 36,000 to 46,000 g/mol, as determined by triple point detection. In some aspects, the branched polyimide has a M _w of 32,000 to 55,000 g/mol, or 32,000 to 55,000 g/mol, or 32,000 to 50,000 g/mol, or 33,000 to 45,000 g/mol, or 34,000 to 44,000 g/mol, or 35,000 to 43,000 g/mol, or 36,000 to 42,000 g/mol, or 32,000 to 40,000 g/mol, or 33,000 to 39,000 g/mol, or 34,000 to 38,000 g/mol, or 34,000 to 44,000 g/mol, or 35,000 to 43,000 g/mol, or 36,000 to 42,000 g/mol, or 37,000 to 41,000 g/mol, or 36,000 to 45,000 g/mol, or 37,000 to 45,000 g/mol, or 38,000 to 44,000 g/mol, or 39,000 to 43,000 g/mol, as determined by triple point detection.

[0079] In some aspects, the polydispersity index (PD I) of the linear polyimide is less than the PDI of the branched polyimide. In particular aspects, the linear polyimide has a PDI of 1.8 to 2.4, preferably 1.9 to 2.2, more preferably 2 to 2.2, and the branched polyimide has a PDI of 2.3 to 3.5, preferably 2.4 to 3.2, more preferably 2.5 to 3.

[0080] In one aspect, the reinforced polyimide composition includes the following: a linear polyimide with a weight average molecular weight of 28,000 to 60,000 g/mol, preferably 30,000 to 50,000 g/mol, more preferably 32,000 to 45,000 g/mol, as determined by SEC using triple point detection; a branched polyimide has a weight average molecular weight of 28,000 to 60,000 g/mol, preferably 30,000 to 50,000 g/mol, more preferably 32,000 to 45,000 g/mol, as determined by SEC using triple point detection; and a PDI of the linear polyimide is about 10% to about 60% less than a PDI of the branched polyimide.

[0081] The reinforced polyimide composition has a UL94 rating of V-l or better, as measured following the procedure of Underwriter's Laboratory Bulletin 94 entitled “Tests for Flammability of Plastic Materials for Parts in Devices and Appliances” (ISBN 0-7629-0082-2), Fifth Edition, Dated Oct. 29, 1996, incorporating revisions through and including Dec. 12, 2003. In an aspect, the polyimide composition has a UL94 rating of V-0 or V-l at a thickness of 0.3, 0.5, 0.75, 0.9, 1, 1.5, 2, or 3 mm. In some aspects, the polyimide composition has a UL94 rating of V-0 at a thickness of 0.3, 0.5, 0.75, 0.9, 1, 1.5, 2, or 3 mm. In a particular aspect, the polyimide composition has a UL94 rating of V-0 at a thickness of 0.5 or 1.5 mm.

[0082] Also provided herein is an article including the reinforced polyimide composition or the polymer composition. Shaped, formed, or molded articles comprising the polyimide or polymer compositions are also provided. The reinforced polyimide or polymer compositions can be molded into useful shaped articles by a variety of methods, such as injection molding, extrusion, rotational molding, blow molding, and thermoforming. A wide variety of articles can manufactured using the polyimide composition or the polymer composition, for example articles of utility in automotive, telecommunication, aerospace, electrical/electronics, battery manufacturing, wire coatings, transportation, food industry, and healthcare applications. Such articles can include films, fibers, foams, thin sheets, small parts, coatings, fibers, preforms, matrices for polymer composites, or the like. The foams can be open or closed cell. In an aspect the foams are closed cell foams. The articles can be extruded or molded, for example injection molded. Components for electronic devices and components for sterilizable medical articles can be specifically mentioned. Thin-wall components manufactured by injection molding can also be specifically mentioned, such as a wall having a thickness from 0.1 to 10 millimeters (mm), or 0.2 to 5 mm, or 0.5 to 2 mm. In some aspects, a film can be manufactured by solution-casting or melt processing the polyimide composition or the polymer composition described herein.

[0083] The reinforced polyimide composition or the polymer composition can be incorporated as one or more layers of a multilayer composite article. For example, the same or a different reinforced polyimide composition, or its corresponding polymer composition, can be two or more layers of the multilayer composite article. The other layers of the multilayer composite article can include the same or different reinforcing materials such as the fibers of silica glass, non-silica glass fibers, carbon fibers, or a combination of fibers thereof, in combination with known thermoplastic materials. Also, the other layers of the multilayer composite article may not have any reinforcing material, or some of the other layers can include reinforcing materials and other layers may not. Suitable thermoplastic substrate materials include a multitude of thermoplastics, for example, but not limited to, polyethylene or polypropylene, polyamides, such as nylon-6, nylon-6,6, nylon-6,12, polycarbonates, e.g., aromatic polycarbonates containing bisphenol A, and thermoplastic polyurethanes.

[0084] Also provided herein is a multilayer composite article that includes at least one layer, incorporating the reinforced polyimide composition described herein, or the corresponding polymer composition. The multilayer composite can include at least two, preferably at least three, mutually superposed layers that incorporate at least one layer that includes the reinforced polyimide composition described herein, or the corresponding polymer composition. In the case of a three or more layers of a multilayer composite article, the layers can be defined relative to one another as two external layers and at least one internal layer. There is in principle no limit to the number of layers in the multilayer composite material.

[0085] The reinforced polyimide compositions are further illustrated by the following non-limiting examples. EXAMPLES

[0086] Weight average molecular weight (M _w ) was measured by gel permeation chromatography (GPC, EcoSECHLC-8320, Tosoh Bioscience) equipped with a Wyatt MiniDAWN TREOS multi-angle light scattering detector, a differential refractive index detector (DRI), and a UV detector. The PEIs were dissolved in DMF, and the flow rate was 0.5 mL min ¹ . The column set consisting of a SuperH-H guard column (4.6 mm ID x 3.5 cm, 4 pm), a SuperH- H guard column (6.0 mm ID x 15 cm, 4 pm), and two SuperH-H guard columns (6.0 mm ID x 15 cm, 4 pm) carried out the separation. Both the detectors and columns were maintained at 30°C. M _w was determined by a triple point detector.

[0087] Polydispersity index (PDI) was determined by size exclusion chromatography- multiple angle light scattering SEC-MALS in chloroform using dn/dc=0.271 or determined by GPC using polystyrene standards (or a triple-point detector).

[0088] Glass transition temperature (T _g ) and melting temperature (T _m ) were determined using Differential Scanning Calorimetry (DSC) according to ASTM D3418. The test was performed using a TA Q1000 DSC instrument. In a typical procedure, a polymer sample (10-20 milligrams) was heated from 40 to 400 °C at a rate of 20 °C /min, held at 400 °C for 1 minute, cooled to 40 °C at a rate of 20 °C /min, then held at 40 °C for 1 minute, and the above heating/cooling cycle was repeated. The second heating cycle is usually used to obtain the T _g and T _m .

[0089] Tensile tests were performed on an Instron 5500R at a cross-head speed of 5 mm/min at 23°C according to ASTM D638-14. The maximum elongation was averaged over five specimens.

[0090] Melt rheological studies were performed on an AR-G2 rheometer (TA Instruments) and two 25-mm-diameter parallel plates were used.

[0091] Melt stability studies were performed at 380°C for 30 minutes under nitrogen on a rheometer with a sandwich, or parallel-late/cone-plate, fixture according to ASTM D4440. Viscosity data (poise = P) was compared between the initial value and 30 minutes (final value). Pellets were dried for approximately 2 to 4 hours at 150°C prior to testing.

[0092] The linear and branched polyetherimides listed in Table 1 with the molecular weights and PDIs listed in Table 2 were used in the Examples and Comparative Example.

Unless specifically indicated otherwise, the amount of each component is in weight percent (wt%) in the following examples, based on the total weight of the composition.

Table 1

Table 2

[0093] Linear and branched polyetherimides (PEI) with respective absolute molecular weight (Mw, Mn, and PDI) in Table 2 were blended into compositions indicated in Table 3A and Table 3B, listed as weight percent per component.

Table 3A a total branched mole percent was determined according to Equation 1

Table 3B a total branched mole percent was determined according to Equation 1 [0094] The extruder type for preparing the samples was a twin-screw, vacuum vented, 30 mm Werner Pfleiderer twin screw extruder with six barrel sections. Extrusion was performed at a barrel temperatures starting at 338 °C (640.4 °F) and incrementing to reach 360 °C (680 °F) at zone 6, die temperature of 371 °C (699.8 °F), screw speed of 300 rpm, and output of 40 kilograms per hour (kg/h). Extrusion was run with vacuum venting. The twin-screw extruder had enough distributive and dispersive mixing elements to produce good mixing between the components. The melt processed compositions exited the extruder through small exit holes in a die. The resulting strands of molten resin were cooled by passing the strands through a water bath.

[0095] As indicated in Tables 3A-3B, fourteen example reinforced polyimide compositions and two comparative examples were dry blended and extruded. Reinforced polyimide compositions were designed to blend 0.3 mol% (BPEI-1), 1.5 mol% (BPEI-2), or 3.0 mol% (BPEI-3) branched PEI with linear PEI (PEI-38k) and chopped glass fiber. PEI and BPEI pellets were dry blended and extruded on a twin-screw extruder (T-3). Zone temperatures were set to start at 338 °C (640.4 °F) and incrementing to reach 360 °C (680 °F) at Zone 6. The feed (Zone 0) temperature was 260 °C (500 °F). The die temperature was set at 371 °C (699.8 °F) with the screw speed at 100 rpm. Extrusion was run with vacuum venting.

[0096] The thermoplastic properties of glass fiber reinforced PEI (CE1 and CE2) and glass fiber reinforced branched PEI blends (E1-E7 and E8-E14) were compared and are listed in Table 4A and Table 4B. CE1 is comparative to E1-E7, and CE2 is comparative to E8-14, each having corresponding amount of glass fiber of 20 wt% and 40 wt%, respectively.

Table 4A

Table 4B

² Apparent viscosity measured as Pascals second (Pa-s) at 360 °C;

³ Viscosity change measured at 380 °C for 1800 seconds

[0097] In addition, the apparent viscosity (at 640 s ¹ and 5000 s ¹ at a shear rate of 360 °C) for a 20 wt% glass fiber reinforced blend of linear and branched PEI: El, 738 Pa-s and 261 Pa-s, respectively; E2, 630 Pa-s and 221 Pa-s, respectively; E6, 694 Pa-s and 242 Pa-s, respectively; and E7, 580 Pa-s and 216 Pa-s, respectively) are less than the 20 wt% glass fiber reinforced linear PEI (CE1), 752 Pa-s and 281 Pa-s, respectively) as indicated by the data listed in Table 4. Moreover, the apparent viscosity at a shear rate of 5000 s ¹ for each example composition E1-E7 is less than that of CE1. Also, the apparent viscosity for each of 40 wt% glass fiber reinforced blend of linear and branched PEI (E8-E14) are less than the 40 wt% glass fiber reinforced linear PEI (CE2) at both a shear rate of 640 s ¹ and 5000 s ¹ at 360 °C. Accordingly, a reduction in apparent viscosity is obtained by using a blend of linear and branched PEI with glass fiber over a wide range of blended linear and branched, reinforced polyimide compositions. This wide range of blending compositions can include a range of respective weight ratios of linear to branched PEI (PEI blend) across a weight percentage range of glass fiber, for any one PEI blend.

[0098] Percent viscosity change (at 380 °C for 1800 s) for example compositions E1-E7, which include glass fiber (20 wt%) reinforced blends of PEI and branched PEI, are equal to or greater than that of CE1. See, Table 4. For examples E3 and E7, which include 77 wt% of branched PEI, exhibit a 30% percent increase in percent viscosity change compared to CE1. Percent viscosity change for each of example compositions E8-E16, 40 wt% glass fiber reinforced PEI blends, is greater than that of CE2, 40% glass fiber with linear PEI. In fact, Ell with as little as 11 wt% branched PEI in the PEI blend exhibits a 140% percent increase in percent viscosity change compared to CE2, and many of the PEI blend example compositions exhibit about a 100% percent increase in percent viscosity change compared to CE2.

[0099] The extruded pellets were molded into shapes suitable for the applicable mechanical testing. Molding used a flat profile of 366 °C (690.8 °F) and with a mold temperature of 149 °C (300 °F). Injection speed was set to 38.1 mm (1.5 inches) per second with a back pressure of 3.4 atm (50 psig) on a 180-ton DeMag injection molding machine. The samples were molded into 3.2 mm ASTM HDT bars, 3.2 mm ASTM Izod bars and ASTM tensile bars, and disks having a diameter of 10.2 cm (4 inches) and a thickness of 0.32 cm (0.125 inches).

[0100] The impact strength (Notched Izod at 23° C and 5 lbf/ft) of glass fiber reinforced PEI blends (E1-E7 and E8-E14) increase with both the amount and molar percentage of branched PEI as indicated by the data of Table 5A and Table 5B, respectively. Hence, all glass fiber reinforced PEI blends exhibit greater impact strength (Notched Izod) than comparable glass fiber reinforced linear PEI within error. In fact, example composition E14 with 40 wt% glass fiber and a relatively high molar percentage of branched PEI (57 wt% branched PEI and 3 wt% linear PEI) exhibits an increase of 28% and 38% of Notched and Unnotched impact strength, respectively, compared to CE2. E2-E7 each had an unnotched Izod impact strength that exceeded the glass-fiber reinforced PES. In comparison to PES, blends E3, E5, and E6 achieved an unnotched impact strength that is 37%, 23%, and 29% greater than PES, respectively.

Table 5A

Table 5B

¹ Measured as Joule per meter (J/m) at 23 °C and 5 pound-force per foot

[0101] For each mechanical property listed in Table 6 A and Table 6B, example compositions with glass fiber reinforced PEI blends (E1-E7 and E8-E14) exhibit greater MPa values than that of glass fiber reinforced linear PEI (CE1 and CE2). In fact, example composition E7 with 20 wt% glass fiber and 77 wt% branched PEI, i.e., a high molar percentage of branched PEI, exhibits an increase of 15% and 31% of flexural and tensile modulus, respectively, and a 11% and 22% increase in flexural and tensile strength, respectively, in comparison to CE1. Similarly, in comparison to CE2, E14 exhibits an increase of 12% and 15% of flexural and tensile modulus, respectively with 33% and 11% increase in flexural and tensile strength, respectively.

[0102] In comparison to a glass-fiber reinforced PES (20 wt% GF), molded samples of blends E2, E4, and E5 achieved an increased flexural strength. Molded samples of blends E3,

E6, and E7 achieved a flexural strength that is 21%, 17%, and 18% greater than PES, respectively, a flexural modulus that is 4%, 2%, and 6% greater than PES, respectively, and a tensile strength that is 8%, 2%, or 6% greater than PES, respectively.

[0103] The inventors surprisingly discovered that a total branched mole percent (TBMP) of less than 1.0 is correlated with an increased impact strength, and in particular with an increased notched Izod impact strength. This is noted in the notched impact strength of E7, where a TBMP of greater than 1.0 resulted in a decreased impact strength relative to CE1 and El to E6. The TBMP can be calculated according to Equation 1 as described herein.

Table 6A

Table 6B

¹ Flexural modulus and flexural strength at yield are measured at 3.2 mm and 1.27 mm/min

² Tensile modulus and tensile strength at break are measured at 23 C and 5 mm/min

[0104] As shown in Tables 7 A and 7B, the polyetherimide-glass fiber example compositions exhibit a glass transition temperature (T _G ) above 200 °C. Moreover, the glass fiber reinforced branched PEI exhibit similar T _G to that of the comparative glass fiber reinforced PEI within error. E1-E7 have a lower T _G than the glass-fiber reinforced PES.

Table 7A

Table 7B

[0105] This disclosure is further illustrated by the following aspects, which are non limiting.

[0106] Aspect 1. A reinforced polyimide composition comprising: 2 to 90 wt%, preferably 20 to 70 wt%, more preferably 20 to 50 wt% of a linear polyimide; 2 to 95 wt%, preferably 5 to 70 wt%, more preferably 10 to 40 wt%, of a branched polyimide; and 5 to 50 wt%, preferably 10 to 45 wt%, more preferably 15 to 45 wt% of a reinforcing material, wherein each weight percent is based on a total weight of the polyimide composition.

[0107] Aspect 2. The reinforced polyimide composition of aspect 1, wherein the reinforcing material is hollow or solid glass spheres, continuous or chopped carbon fibers, continuous or chopped glass fibers, flaked glass, milled glass, continuous or chopped elliptical or flat glass, or a combination thereof.

[0108] Aspect 2a. The reinforced polyimide composition of aspect 1, wherein the reinforcing material is hollow or solid glass spheres, carbon fiberglass spheres, whiskers of silicon carbide or silicon nitride, continuous or chopped carbon fibers, continuous or chopped glass fibers, flaked glass, milled glass, flaked silicon carbide or nitride, flaked aluminum diboride, flaked aluminum, steel flakes, or a combination thereof.

[0109] Aspect 3. The reinforced polyimide composition of aspect 1, wherein the reinforcing material is a glass fiber, carbon fiber, or a combination thereof.

[0110] Aspect 4. The reinforced polyimide composition of any one of the preceding aspects, wherein the branched polyimide is of formula (1) as provided herein.

[0111] Aspect 5. The reinforced polyimide composition of aspect 4, wherein V is a group of formulas (2) as provided herein.

[0112] Aspect 6. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in amount of 15 to 45 wt%, and the reinforced polyimide composition has at least one of the following: a melt flow rate greater than a melt flow rate of a reference composition that comprises the linear polyimide and does not include the branched polyimide, and a same amount of the reinforcing material, as measured at 337°C at a shear load of 6.7 kg, in accordance with ASTM 1238; or an apparent viscosity of less than 1200 Pa-s and greater than 500 Pa-s, and the apparent viscosity is less than an apparent viscosity of the reference composition, as measured at 360°C at a shear rate of 640 s ¹ in accordance with ISO 11443; or an apparent viscosity of less than 400 Pa-s and greater than 180 Pa-s, and the apparent viscosity is less than an apparent viscosity of the reference composition, as measured at 360°C at a shear rate of 5000 s ¹ in accordance with ISO 11443.

[0113] Aspect 7. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in an amount from 15 to 45 wt%, and a reinforced polyimide sample of the polyimide composition has at least one of the following: a notched Izod impact strength of 55 J/m to 95 J/m, and the notched Izod impact strength is greater than a notched Izod impact strength of a reference sample that includes the linear polyimide and does not include the branched polyimide, and a same amount of the reinforcing material, as measured at 23°C in accordance with ASTM D256; or a reverse notched Izod impact strength of 250 J/m to 440 J/m, and the reverse notched Izod impact strength is greater than a reverse notched Izod impact strength of the reference sample, as measured at 23 °C in accordance with ASTM D256; or an unnotched Izod impact strength of 360 J/m to 610 J/m, and the unnotched Izod impact strength is greater than an unnotched Izod impact strength of the reference sample, as measured at 23°C in accordance with ASTM D256.

[0114] Aspect 8. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in an amount from 15 to 45 wt%, and a reinforced polyimide sample has thermal properties within ± 2% to that of a reference sample that includes the linear polyimide and does not include the branched polyimide, and a same amount of the reinforcing material, as the reinforced polyimide sample, wherein the thermal properties are at least one of: a glass transition temperature from 200 to 230°C as measured with differential scanning calorimetry in accordance with D3418 ASTM; or a Vicat B120 softening temperature from 200 °C to 230 °C as measured at 50 Newtons and 50°C/hour in accordance with ISO 306; or a heat deflection temperature from 195 to 215°C as measured at 1.82 MPa and 3.2 mm in accordance with ASTM D648.

[0115] Aspect 9. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in an amount from 15 to 30 wt%, and a reinforced polyimide sample has at least one of the following: a flexural modulus that is 4% to 25% greater than a reference sample, as measured at 3.2 mm/min at 23°C in accordance with ASTM D790; or a tensile modulus that is 8% to 45% greater than a reference sample, as measured at 5 mm/min at 23°C in accordance with ASTM D638, wherein the reference sample includes the linear polyimide, a same amount of the reinforcing material as the reinforced polyimide sample, and does not comprise the branched polyimide.

[0116] Aspect 10. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in an amount from 30 to 45 wt%, and a reinforced polyimide sample has at least one of the following: a flexural modulus that is 2% to 15% greater than a reference sample; or a tensile modulus that is 2% to 20% greater than a reference sample, wherein the reference sample includes the linear polyimide, a same amount of the reinforcing material as the reinforced polyimide sample, and does not comprise the branched polyimide.

[0117] Aspect 11. The reinforced polyimide composition of any one of the preceding aspects, wherein the reinforcing material is present in an amount from 15 to 30 wt%, and a reinforced polyimide sample has at least one of the following: a flexural modulus that is 4% to 25% greater than a reference sample; or a tensile modulus that is 8% to 45% greater than a reference sample, wherein the reference sample includes the linear polyimide, a same amount of the reinforcing material as the reinforced polyimide sample, and does not comprise the branched polyimide.

[0118] Aspect 12. The reinforced polyimide composition of any one of the preceding aspects, wherein the linear polyimide has a Mw of 28,000 to 60,000 g/mol, preferably 30,000 to 50,000 g/mol, more preferably 32,000 to 45,000 g/mol, as determined by SEC using triple point detection, the branched polyimide has a Mw of 20,000 to 60,000 g/mol, preferably 30,000 to 50,000 g/mol, more preferably 32,000 to 45,000 g/mol, as determined by SEC using triple point detection, and a PDI of the linear polyimide is about 10% to about 60% less than a PDI of the branched polyimide.

[0119] Aspect 13. The reinforced polyimide composition of any one of the preceding aspects, wherein the branched polyimide is a polyetherimide of formula (la) as provided herein.

[0120] Aspect 14. The reinforced polyimide composition of any one of the preceding aspects, further comprising an additional polymer different from the linear polyimide and the branched polyimide, wherein the additional polymer is a polyacetal, poly(Ci- ₆ alkyl)acrylate, polyacrylamide, polyacrylonitrile, polyamide, polyamideimide, polyanhydride, polyarylene ether, polyarylene ether ketone, polyarylene ketone, polyarylene sulfide, polyarylene sulfone, polybenzothiazole, polybenzoxazole, polybenzimidazole, polycarbonate, polyester, polyetherimide, polyimide, poly(Ci- ₆ alkyl)methacrylate, polymethacrylamide, cyclic olefin polymer, polyolefin, polyoxadiazole, polyoxymethylene, polyphthalide, polysilazane, polysiloxane, polystyrene, polysulfide, polysulfonamide, polysulfonate, polythioester, polytriazine, polyurea, polyurethane, vinyl polymer, or a combination thereof.

[0121] Aspect 15. An article prepared from the reinforced polyimide composition of any one of the preceding aspects, wherein the article is a film, a fiber, an open-cell foam, a closed cell foam, a thin sheet, a coating, a component of an electronic device, or a component of a medical device.

[0122] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate components or steps herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any steps, components, materials, ingredients, adjuvants, or species that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0123] The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. “Or” means “and/or” unless clearly indicated otherwise by context. Reference throughout the specification to “an embodiment” means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. The described elements may be combined in any suitable manner in the various embodiments. “Combination thereof’ is an open term that includes one or more of the named elements, optionally together with a like element not named.

[0124] As used herein, the term “hydrocarbon” or “hydrocarbyl” refers to a group including carbon and hydrogen; “alkyl” refers to a straight or branched chain, saturated monovalent hydrocarbon group; “alkylene” refers to a straight or branched chain, saturated, divalent hydrocarbon group; “alkylidene” refers to a straight or branched chain, saturated divalent hydrocarbon group, with both valences on a single common carbon atom; “alkenyl” refers to a straight or branched chain monovalent hydrocarbon group having at least two carbons joined by a carbon-carbon double bond; “cycloalkyl” refers to a non-aromatic monovalent monocyclic or polycyclic hydrocarbon group having at least three carbon atoms, “cycloalkenyl” refers to a non-aromatic cyclic divalent hydrocarbon group having at least three carbon atoms, with at least one degree of unsaturation; “aryl” refers to an aromatic monovalent group containing only carbon in the aromatic ring or rings; “arylene” refers to an aromatic divalent group containing only carbon in the aromatic ring or rings; “alkylaryl” refers to an aryl group that has been substituted with an alkyl group as defined above, with 4-methylphenyl being an exemplary alkylaryl group; “arylalkyl” refers to an alkyl group that has been substituted with an aryl group as defined above, with benzyl being an exemplary arylalkyl group; “acyl” refers to an alkyl group as defined above with the indicated number of carbon atoms attached through a carbonyl carbon bridge (-C(=0)-); “alkoxy” refers to an alkyl group as defined above with the indicated number of carbon atoms attached through an oxygen bridge (-0-); and “aryloxy” refers to an aryl group as defined above with the indicated number of carbon atoms attached through an oxygen bridge (-0-). The prefix "halo" means a group or compound including one more halogen (F, Cl, Br, or I) substituents, which can be the same or different. The prefix “hetero” refers to a group or compound that includes at least one heteroatom (e.g., 1, 2, or 3 heteroatoms), wherein each heteroatom is independently N, O, S, or P.

[0125] Unless otherwise indicated, each of the foregoing groups can be unsubstituted or substituted, provided that the substitution does not significantly adversely affect synthesis, stability, or use of the compound. The term “substituted” as used herein means that at least one hydrogen on the designated atom or group is replaced with another group, provided that the designated atom’s normal valence is not exceeded. Exemplary groups that can be present on a “substituted” position include, but are not limited to, cyano; hydroxy; nitro; azido; alkanoyl (such as a C2-6 alkanoyl group such as acyl); carboxamido; Ci- ₆ or C1-3 alkyl, cycloalkyl, alkenyl, and alkynyl groups; Ci- ₆ or C1-3 alkoxy; C6-10 aryloxy such as phenoxy; Ci- ₆ alkylthio; Ci- ₆ or Ci- 3 alkylsulfinyl; Ci- ₆ or C1-3 alkylsulfonyl; aminodi(Ci- ₆ or Ci-3)alkyl; C6-12 aryl having at least one aromatic ring (e.g., phenyl, biphenyl, naphthyl, or the like, each ring either substituted or unsubstituted aromatic); or C7-19 arylalkyl having 1 to 3 separate or fused rings. When a compound is substituted, the indicated number of carbon atoms is the total number of carbon atoms in the compound or group, including those of any substituents.

[0126] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears. Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this disclosure belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety.

[0127] While particular aspects have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.