Abstract: Polyetherimide oligomers having crosslinking end cap moieties which provide improved solvent-resistance to cured composites are generally represented by the formula: ##STR1## wherein X=--O-- or --S--; ##STR2## n=1 or 2; ##STR3## E=allyl or methallyl; R=a trivalent C.sub.(6-13) aromatic organic radical;R.sub.1 =any of lower alkyl, lower alkoxy, aryl, or substituted aryl;R'=a divalent C.sub.(6-30) aromatic organic radical;j=0, 1, or 2; andG=--CH.sub.2 --, --O--, --S--, or --SO.sub.2 --Blends generally comprise substantially equimolar amounts of the oligomers and a comparable, compatible, noncrosslinking, etherimide polymer of substantially the same backbone. The crosslinkable oligomers are made by reacting substituted phthalic anhydrides with hydroxyaryl amines and suitable crosslinking end cap reactants, or by self-condensation of phthalimide salts followed by capping the polymers.

Abstract: A heat resistant adhesive composition comprising an admixture of a modified bismaleimide (BMI) resin, a modified polyamide-imide and a solvent. The bismaleimide is modified by barbituric acid and/or the derivatives thereof and the polyamide-imide is modified by an epoxy resin. The overall solid content of the heat resistant adhesive composition is in the range of about 15 to 50 percent by weight, wherein solid contents per overall solid content of the modified bismaleimide resin and the modified polyamide-imide are 60 to 90 percent and 10 to 40 percent, respectively.

Abstract: A resin composition for sealing semiconductors which comprises an organic component (A) which contains (a) a polymaleimide compound represented by the formula (I): ##STR1## wherein R.sub.1 is a m-valent organic group having two or more carbon atoms and m is an integer of two or more and (b) a phenolic aralkyl resin represented by the formula (II): ##STR2## wherein X is a divalent group having the formula ##STR3## and n is an integer of from 0 to 100, or contains a mixture of the phenolic aralkyl resin and a phenol, and component (B) which contains an inorganic filler.

Abstract: A method for the preparation of a polyimide containing reversible crosslinks comprising the step of curing a monomer having the formula ##STR1## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR2## R and R' are as defined above and n is an integer from 10 to 100. The polyimide may be converted to a soluble polymer by cleaving the disulfide bond in the presence of a solvent and a reducing agent. The reduced polymer may be reformed into the polymer in an oxidation step or into a modified polyimide in other reaction steps. Copolymerization processes are also disclosed.

Abstract: Thermosetting resins for use in high performance fiber-reinforced composites are toughened without compromising their processability by the inclusion of micron-sized particles of thermoplastic material which are solid at ambient temperatures but solubilize in the resins at a temperature below the gel temperature of the thermosetting resin. By appropriate selection of the solubilization temperature (or temperature range) of the thermoplastic material, one achieves a composite product having intralaminar or interlaminar toughness emphasized or a combination of both. The invention is of particular utility when applied to bismaleimide resin systems.

Abstract: The present invention relates to a polyimide resin composition and products, especially storage stable polyimide pre-pregs, manufactured therefrom with improved processing properties comprising (A) the reaction product of a polyimide, an alkenylphenol or an alkenylphenol ether, and tribromophenyl-maleimide, (B) an ionic or free-radical polymerization catalyst and (C) phenothiazine derivatives.

Abstract: A polymer composition especially suitable for producing fibre-reinforced structures having advantageous fracture toughness comprises a polyarylsulphone component and a thermoset resin component, each of which components is present at least partly as a phase continuous in at least one dimension. Preferred polyarylsulphones contain repeating units (PhSO.sub.2 Ph).sub.n and (Ph).sub.a linked through ether and/or thioether, where Ph is phenylene, n=1 to 2 and a=1 to 3; and such polyarylsulphones having amino end groups are provided as new compounds. The compositions can be made by spinodal decomposition of a mixture of the polyarylsulphone and a thermoset resin precursor.

Abstract: This invention relates to mixtures of short fibers of varying lengths, diameters and aspect ratios composed of an anisotropic polymer, to compositions containing said fibers and one or more thermoplastic or thermoset resins, and to a process for forming said mixtures.

Abstract: Tetrapolyimide films derived from 3,3',4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic acid dianhydride, p-phenylene diamine and 4,4'-diaminodiphenyl ether, and their preparation, are described. The tetrapolymer films have low water absorption, low coefficients of thermal and hygroscopic expansion, high modulus and are caustic etachable and can be used in flexible printed circuit and tape automated bonding applications.

Abstract: The imidization temperature of poly(amide-acid) compositions derived from tetracarboxylic acid dianhydrides can be lowered by use of a bis(aminophenoxyphenyl) phosphine oxide in the diamine component which is reacted with the dianhydride. These homo- or copolyimides can be cyclized without use of catalysts or excessive temperature which can product undesired side reactions. Tough film forming materials can be produced which show excellent thermo-oxidative stability and high char yields even at 800.degree. C. in air.

Abstract: Polyimide oligomers include (1) linear, monofunctional crosslinking oligomers prepared by condensing a monoanhydride end cap with a diamine that includes alternating ether and "Sulfone" (--SO.sub.2 --, --S--, --CO--, --(CF.sub.3).sub.2 C--, or --(CH.sub.3).sub.2 C--) linkages connecting alternating aromatic radicals and with a dianhydride (or dianhydride mixture), particularly the unsaturated, aliphatic dianhydride commonly known as MCTC; (2) linear, mono- or difunctional crosslinking oligomers prepared by condensing an amine end cap with a diamine and a dianhydride; and (3) multidimensional, crosslinking oligomers having an aromatic hub and at least three radiating arms connected to the hub, each arm including a crosslinking end cap at its distal end and at least one imide linkage.Blends, prepregs, and composites can be prepared from the oligomers.

Abstract: This invention relates to thermosettable bismaleimide resin compositions, and to cured bismaleimide thermoset resins.The compositions of the present invention contain an additive which is the reaction product of (i) an epoxide, and (ii) a second reactant selected from an aromatic polyhydroxyl, an aromatic amide or an aromatic amine. The thermoset resins having surprising strength and modulus properties, and are suitable for use in the preparation of composite materials.

Abstract: Curable thermosetting prepolymerized imide resin compositions are prepared by chemically reacting, at a temperature below 150.degree. C., a liquid mixture of carboxy-terminated polybutadiene/acrylonitrile (CTBN) and a co-reactant comprising at least one N,N'-bisimide of an unsaturated carboxylic acid of formula (I) where B represents a divalent radical containing a carbon-carbon double bond and A represents a divalent radical having at least two carbon atoms to yield a curable thermosetting prepolymerized imide resin composition containing copolymerized CTBN and co-reactant. A resin composition prepared by this method may be cured at a temperature between 100.degree. C. and 350.degree. C. to yield a fully cross-linked polyimide matrix containing a dispersion of phase-separated solid particles of copolymerized CTBN and co-reactant, the matrix having a lapshear strength at 20.degree. C. at least 50% greater than that of a fully cross-linked polyimide cured from the co-reactant alone.

Abstract: This invention is a process for making a semi-interpenetrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide having the following repeating unit: ##STR1## Provided is an improved high temperature matrix resin which is capable of performing at 316.degree. C. in air for several hundreds of hours. This resin has significantly improved toughness and microcracking resistance, excellent processability and mechanical performance, and cost effectiveness.

Abstract: Polyetherimide oligomers having crosslinking end cap moieties which provide improved solvent-resistance to cured composites are generally represented by the formula: ##STR1## wherein X=--O-- or --S--; ##STR2## n=1 or 2; ##STR3## E=allyl or methallyl; R=a trivalent C.sub.(6-13) aromatic organic radical;R.sub.1 =any of lower alkyl, lower alkoxy, aryl, or substituted aryl;R'=a divalent C.sub.(6-30) aromatic organic radical;j=0, 1, or 2; andG=--CH.sub.2 --, --O--, --S--, or --SO.sub.2 --The crosslinkable oligomers are made by reacting substituted phthalic anhydrides with hydroxyaryl amines and suitable crosslinking end cap reactants, or by self-condensation of phthalimide salts followed by capping the polymers.

Abstract: An addition type imide resin prepolymer is obtained by a reaction of unsaturated bisimide of 1.0 mol to diamine of 0.25 to 0.43 mol and an addition of polyamine having three or more benzene rings. The prepolymer is thereby made to contain substantially no unreacted diamine component which affects human body of operators, and to have remarkably excellent heat resistance and adhesive properties, while effective to restrain a production of any component of a molecular weight exceeding 15,000.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or teThis invention was made with Government support under F33615-88-C-5409 awarded by the Department of the Air force. The Government has certain rights in this invention.

Abstract: A thermosetting resin composition formed of a polyaminobismaleimide resin, which is composed of a bismaleimide compound and a diamine compound, and a fibrous reinforcing material. The composition has excellent impact resistance and toughness while retaining conventional high heat resistance.

Abstract: Multicomponent polymeric compositions comprising self-prontonated sulfonic acid-substituted polyaniline compositions or derivatives thereof and at least one insulating polymer are disclosed. The sulfonated polyaniline compositions have faster electronic and optical responses to electrochemical potentials, improved environmental stability, and improved solubility than the parent polymer, polyaniline. The multicomponent sulfonated polyaniline/insulating polymer compositions are useful in electronic, chemical, electrochemical, and optical microelectric applications which use and control the chemical and physical properties of the sulfonated polyaniline compositions.

Abstract: This invention is a semi-interpenetrating polymer network which includes a high performance thermosetting polyimide having a nadic end group acting as a crosslinking site and a high performance linear thermoplastic polyimide having the following repeating unit: ##STR1## Provided is an improved high temperature matrix resin which is capable of performing at 316.degree. C. in air for several hundreds of hours. This resin has significantly improved toughness and microcracking resistance, excellent processability and mechanical performance, and cost effectiveness.

Abstract: A novel polyfunctional maleimide-based thermosettable resin composition comprising: (a) at least one polyfunctional maleimide compound selected from the group consisting of bismaleimide and polymaleimide, and (b) at least one ether derivative of an alkenylphenol.

Abstract: Described herein is a process for the chlorination of amide containing oligomers and/or polymers by reacting the oligomers and/or polymers with an aqueous hypochlorous acid solution containing at least 5% by weight of hypochlorous acid and being essentially free of chlorine, chlorate, and alkali metal ions, said process being conducted in an aqueous medium.

Abstract: A heat resistant adhesive composition comprising a specific polyamic acid solution and a bis-maleimide compound exhibits flexibility and excellent heat resistance after bonding two material bodies, and therefore, it can be suitably used for producing of flexible metal-clad laminates, double-sided flexible metal-clad laminates, and multilayer printed circuit boards, and for attaching coverlay films to printed circuit boards.

Abstract: A tough, high performance polyimide is provided by reacting a triple bond conjugated with an aromatic ring in a bisethynyl compound with the active double bond in a compound containing a double bond activated toward the formation of a Diels-Adler type adduct, especially a bismaleimide, a biscitraconimide, or a benzoquinone, or mixtures thereof. Addition curing of this product produces a highly linear polymeric structure and heat treating the highly linear polymeric structure produces a thermally-stable aromatic addition-type thermoplastic polyimide, which finds utility in the preparation of molding compounds, adhesive compositions, and polymer matrix composites.

Abstract: Polyphasic resin blends and particularly polycarbonate/polyester blends, are prepared with modifiers comprising combinations of polyorganosiloxane/polyvinyl-based graft copolymer(s), polyorganosiloxane-based graft copolymer(s) and/or diene rubber-based graft copolymer(s), imparting a wide range of physical properties to the blends.

Abstract: A thermosetting resin composition comprising a maleimide compound having in the molecule thereof, at least one N-substituted maleimide group and an epoxy resin having a double bond conjugated with an aromatic ring is easily workable and which yields cured products having improved heat resistance.

Abstract: The present invention is connected with a process for preparing a novel photosensitive polyimide precursor having excellent shelf stability and high sensitivity and containing less impurities.The process for preparing a photosensitive heat-resistant polymer containing a repeating unit represented by the formula (III) comprises the step of reacting a photosensitive group-containing isoimide represented by the formula (I) with a diamine represented by the formula (II) at a temperature of 0.degree. to 100.degree. C. in the presence of a solvent: ##STR1## wherein R.sup.1 is independently a tetravalent carbon cyclic aromatic group or heterocyclic group; R.sup.2 is independently an aliphatic group having at least 2 carbon atoms, an alicyclic group, an aromatic aliphatic group, a carbon cyclic aromatic group, a heterocyclic group or a polysiloxane group; R.sup.3 is a monovalent organic group having a photosensitive unsaturated group; and D is an oxygen atom or .dbd.N--R.sup.3.

Abstract: Expanded material obtained by heating a composition comprising at least one hermosetting nadimide resin, said heating being performed at a temperature and during a period which are sufficient to cause the expansion of said composition by release of cyclopentadiene. A nadimide resin of the polyimide type and having a number average molecular weight of 600 to 10,000 is preferably used. The composition further comprises preferably 1% to 50% by weight of a linear, preferably thermostable polymer.

Abstract: Polycarbonate and polyester blends are prepared with a combination of modifiers comprising a multi-stage polyorganosiloxane-based graft polymer composition and a diene rubber-based graft polymer composition imparting a wide range of excellent physical properties on the PC and PE blends.

Abstract: Ethynyl terminated imidothioethers (ETIs) are prepared by the reaction of a dimercaptan, such as 4,4'-dimercaptodiphenyl ether, and an ethynyl containing maleimide, such as N-(3-ethynylphenyl)maleimide. Blends of these ETIs and ethynyl terminated polymeric materials, such as ethynyl terminated sulfones and ethynyl terminated arylene ethers, are also prepared. These resin blends exhibit excellent processability, and the cured blends show excellent fracture toughness and solvent resistance, as well as excellent adhesive and composite properties.

Abstract: Polyimide oligomers include (1) linear, monofunctional crosslinking oligomers prepared by condensing a monoanhydride end cap with a diamine that includes alternating ether and "sulfone" (--SO.sub.2 --, --S--, --CO--, --(CF.sub.3).sub.2 C--, or --(CH.sub.3).sub.2 C--) linkages connecting alternating aromatic radicals and with a dianhydride (or dianhydride mixture), particularly the unsaturated, aliphatic dianhydride commonly known as MCTC; (2) linear, mono- or difunctional crosslinking oligomers prepared by condensing an amine end cap with a diamine and a dianhydride; and (3) multidimensional, crosslinking oligomers having an aromatic hub and at least three radiating arms connected to the hub, each arm including a crosslinking end cap at its distal end and at least one imide linkage.Blends, prepregs, and composites can be prepared from the oligomers.

Abstract: Bismaleimide-containing resin systems suitable for preparing structural adhesives and prepregs having superior tack and drape are disclosed. These resin systems, which have improved uniformity and superior resistance to microcracking, contain finely dispersed bismaleimide particles, and are produced by slurry mixing bismaleimide component(s) with one or more liquid comonomers.

Abstract: The present invention relates to a thermosetting resin composition comprising about 100 parts by weight of a polyimide and from 5 to about 100 parts by weight of a bismaleimide having a similar structure and processes for preparing the same.

Abstract: Disclosed is a thermosetting resin composition comprising (a) a preliminary reaction product between a polyamino compound and an unsaturated bismaleimide compound, (b) an epoxy group-containing vinyl compound, (b') a vinyl group-free aliphatic or aromatic halogenated epoxy compound, (c) an epoxy curing agent and (d) a radical polymerization initiator as indispensable components. This composition is characterized in that the vinyl group-free aliphatic or aromatic halogenated epoxy compound as the component (b') is incorporated. This unsaturated bismaleimide type thermosetting resin composition is excellent in not only heat resistance and strength but also flame retardancy and light weight characteristic.

Abstract: Polyetherimide oligomers having crosslinking end cap moieties which provide improved solvent-resistance to cured composites are generally represented by the formula: ##STR1## wherein X=--O-- or --S--; ##STR2## n=1 or 2; ##STR3## E=allyl or methallyl; R=a trivalent C.sub.(6-13) aromatic organic radical;R.sub.1 =any of lower alkyl, lower alkoxy, aryl, or substituted aryl;R'=a divalent C.sub.(6-30) aromatic organic radical;j=0, 1 or 2; andG=--CH.sub.2 --, --O--, --S--, or --SO.sub.2 --Blends generally comprise substantially equimolar amounts of the oligomers and a comparable, compatible, noncrosslinking, etherimide polymer of substantially the same backbone. The crosslinkable oligomers are made by reacting substituted phthalic anhydrides with hydroxyaryl amines and suitable crosslinking end cap reactants, or by self-condensation of phthalimide salts followed by capping the polymers.

Abstract: A novel polyfunctional maleimide-based thermosettable resin composition comprising: (a) at least one polyfunctional maleimide compound selected from the group consisting of bismaleimide and polymaleimide, and (b) at least one ether derivative of an alkenylphenol.

Abstract: The resin composition which contains thermosetting resin as Component (A), a thermoplastic resin as Component (B), and at least one compound selected from the group consisting of an epoxy resin capable of dissolving the thermoplastic resin and a reactive diluent possessing at least one epoxy group as Component (C) in a ratio such that the proportions of Components (A), (B), and (C) fall respectively in the ranges of 30 to 96% by weight, 2 to 50% by weight, and 2 to 49% by weight, based on the total weight of the resin composition. The resin composition is capable of producing a molded article combining the highly satisfactory mechanical and thermal properties of a thermosetting resin and the highly satisfactory toughness of a thermoplastic resin.

Abstract: A curable thermosetting prepolymerized imide resin composition is prepared by chemically reacting, at a temperature below 150.degree. C., a liquid mixture of a carboxy-terminated polybutadiene/acrylonitrile (CTBN) and a co-reactant containing at least one N,N'-bisimide of an unsaturated carboxylic acid of general formula (I) ##STR1## where B represents a divalent radical containing a carbon-carbon double bond and A represents a divalent radical having at least two carbon atoms, at least one monoimide, and at least one organic hydrazide, to yield a curable thermosetting prepolymerized imide resin composition containing copolymerized CTBN and co-reactant. A resin composition prepared by this method may be cured at a temperature between 100.degree. C. and 350.degree. C. to yield a fully cross-linked polymimide matrix containing a dispersion of phase-separated solid particles of copolymerized CTBN and co-reagent, said matrix having a lap shear strength at 20.degree. C.

Abstract: Prereact modifiers prepared by reacting a propenylphenol with an epoxy resin are useful in toughening heat curable bismaleimide resin systems so as to minimize impact produced damage, and which have exceptional gel times.

Abstract: Alpha, alpha', alpha"-tris(4-cyanatophenyl)-1,3,5-triisopropylbenzenes are new and useful for preparing high heat resistant resins having a low dielectric constant, particularly for electrical applications.

Abstract: A thermosetting resin composition is prepared by mixing(A) a phenol novolak resin having hydroxy groups and allyl-etherified hydroxy groups,(B) a polymaleimide compound having two or more maleimide groups in the molecule, and(C) at least one silicone resin having the following formula (I); ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, are methyl or phenyl; R.sub.3 and R.sub.4, which may be the same or different, are methyl, phenyl, hydrogen or a group having an amino group or an epoxy group but at least one of R.sub.3 and R.sub.4 is hydrogen or a group having an amino group or an epoxy group; and l and m, which may be the same or different, are a number of 0-400. The thermosetting resin composition of the present invention can be suitably used for encapsulating electric devices, for example, and gives, by curing, a cured resin product of high quality.

Abstract: A semiconductor encapsulating material is obtained from a polyimide resin composition comprising (A) a polyaminobismaleimide resin, (B) a silicone monomer and/or oligomer having a hydroxyl or alkoxyl group bonded to a silicon atom and mixtures thereof, and (C) an inorganic filler wherein the weight ratio of polyaminobismaleimide resin (A) to silicone component (B) ranges from 99.5/0.5 to 70/30, and the weight ratio of polyaminobismaleimide resin (A) to inorganic filler (C) ranges from 100/50 to 100/1000.

Abstract: There is disclosed a modified reaction resin with a content of 50 to 98% by weight of a liquid reaction resin or reaction resin mixture processed into thermosetting plastic with a suitable reactive group of sufficient number for the hardening process and 2 to 50% by weight of one or more three-dimensional crosslinked polyorganosiloxane rubbers, which are held in the reaction resin matrix in finely divided state as polyorganosiloxane rubber particles with a diameter of from 0.01 to 50 micrometers, together with small quantities of other auxiliary materials. The rubber particles have reactive groups on their surfaces, which in turn in the presence of auxiliary media serving as reactive components can react chemically with the reaction resin.There is also disclosed a process for the production of the modified reaction resins and their use for the production of fracture and impact resistant, also definitively shaped thermosetting plastics, fiber-reinforced plastics, insulation materials and laminated plastic.

Abstract: Polyetherimide oligomers having crosslinking end cap moieties which provide improved solvent-resistance to cured composites are generally represented by the formula: ##STR1## wherein X=--O-- or --S--; ##STR2## n=1 or 2; ##STR3## E=allyl or methallyl; R=a trivalent C.sub.6-13) aromatic organic radical;R.sub.1 =any of lower alkyl, lower alkoxy, aryl, or substituted aryl;R'=a divalent C.sub.6-30) aromatic organic radical;j=0, 1, or 2; andG=--CH.sub.2 --, --O--, --S--, or --SO.sub.2 --Blends generally comprise substantially equimolar amounts of the oligomers and a comparable, compatible, noncrosslinking, etherimide polymer of substantially the same backbone. The crosslinkable oligomers are made by reacting substituted phthalic anhydrides with hydroxyaryl amines and suitable crosslinking end cap reactants, or by self-condensation of phthalimide salts followed by capping the polymers.

Abstract: Thermoplastic compositions and composites are produced which have fewer and smaller voids with more consistent dimensions compared to conventional unreinforced and fiber reinforced thermoplastics. The high modulus thermoplastic contains silicone semi-interpenetrating polymer networks which are formed by vulcanization within the thermoplastic and initiated during melt processing. Parts molded from the compositions are more homogeneous, with evenly distributed voids, thus reducing the possibility of strss fractures. The compositions are particularly useful in the molding in thick cross-section and variable thickness parts and have been found to have increased thermal stability.

Abstract: This invention relates to novel curable compositions comprising (a) a first component comprising an aromatic polymer having a first preponderant repeat unit and (b) a second component comprising an acetylene, maleimide, or vinyl terminated poly(imide) or poly(isoimide) or precursor thereof, which second component is compatible with the first component, has 1 to 300 second preponderant repeat units which are different from the first preponderant repeat units of the first component, is substantially free of elemental sulfur and reactive divalent sulfur, and is present in an amount effective to substantially cure the composition. The compositions are useful as adhesives, coatings and matrix resins for fiber reinforced composites. They exhibit improved adhesion to various substrates, increased tensile strength and improved resistance to cracking. The invention also relates to the composition which contains a reinforcing filler. The invention also relates to the composition after it has been cured.

Abstract: Reaction product of a polyimide and a secondary/tertiary polyamine and/or primary/tertiary polyamine, and/or protected primary/tertiary polyamine, and use thereof in electrophoretic deposition.

Abstract: High modulus thermoplastic compositions and composites are produced which exhibit enhanced melt integrity and strength, allowing the composites to be melt-drawn to smooth surfaced, high tolerance profiles, such as thin-walled tubing, wire, coatings, films, etc. The melt integrity is improved by adding to the thermoplastic prior to or during thermoplastic melt processing a silicone component which will be vulcanized within the thermoplastic to form a silicone semi-interpenetrating polymer network initiated during the melt processing of the thermoplastic. The composition contains about 0.1 to 20, and preferably about 1 to 4 weight percent of the silicone network, and may also contain fibrous reinforcement and/or filler/modifiers.

Abstract: Storage-stable heat-curable mixtures are described which contain(A) a polyimide which contains in the molecule at least two radicals of formula I ##STR1## wherein D is a divalent radical with a C.dbd.C double bond, (B) an alkenylphenol,(C) an epoxide group-free adduct of an epoxy resin with excess alkenylphenol or(D) a polyimide which is soluble in organic solvents or a mixture of (C) and (D).These mixtures are employed for example as laminating resins or electro-resins, as adhesives or adhesive films for application at high temperatures, or for the preparation of coatings.

Abstract: Polyimide copolymers which are reaction products of active methylene compounds and N,N'-bismaleimide derivatives are improved by incorporating them with 2-20% by weight of a polyetherimide polymer having arylimide bonds, arylene bonds and ether bonds. The polymer blend is useful in films, moldings, prepregs, laminates and filled composites which are particularly useful in structural components which have stability at high temperatures.