Abstract: Woven fabric of continuous, untwisted carbon yarn is impregnated with a modified cyanate ester resin or oligomer, preferably at least about 10% by weight of the combined weight of the cured resin and fabric. The cured fabric may be employed as a wet friction material suitable for use in transmission fluid couplings, and the like. The cured composite sheet can be backed with an adhesive film or liquid bonding paste for ease of bonding to one side of the metal portion of the transmission or clutch. Where thicker material is required, two or more cured composite sheets can be bonded together for applications such as transmissions.

Abstract: Woven fabric of continuous, untwisted carbon yarn is impregnated with a modified cyanate ester resin or oligomer, preferably at least about 10% by weight of the combined weight of the cured resin and fabric. The cured fabric may be employed as a wet friction material suitable for use in transmission fluid couplings, and the like. The cured composite sheet can be backed with an adhesive film or liquid bonding paste for ease of bonding to one side of the metal portion of the transmission or clutch. Where thicker material is required, two or more cured composite sheets can be bonded together for applications such as transmissions.

Abstract: The subject invention relates to a toughened epoxy matrix formulation useful as a prepreg for fiber reinforcements comprising at least two epoxy components, an amine hardener and about 10%-25% of a micropulverized polyimide thermoplastic having a molecular weight of from about 20,000 to about 100,000 and Tg of at least about 220.degree. C. The invention further relates to a process for preparing a toughened epoxy matrix formulation comprising:a. preheating a blend of at least two epoxy compounds to a temperature of about 130.degree. F. to about 140.degree. F.;b. blending into the epoxy blend from step (a) a micropulverized polyimide thermoplastic;c. mixing the blend of epoxy and thermoplastic at a temperature of about 110.degree. F. to about 130.degree. F.; andd. adding to the blend of epoxy and thermoplastic an amine hardener and mixing at about 110.degree. F. to about 130.degree. F. until a low mix viscosity is obtained.

Abstract: A process for producing a dialkyl ester (i.e. BTDE) from its corresponding dianhydride (i.e., BTDA) comprising mixing the dianhydride, an organic solvent, solid catalyst and an alcohol capable of reacting with the dianhydride stirring the solution until the dianhydride and alcohol have reacted to form the dialkyl ester, separating the dialkyl ester from the catalyst and drying the ester to form a solid paticulate product. The product has a purity of over 85%.

Abstract: A catalyst for forming ambient temperature stable diamino-diphenyl sulfone-epoxy composition comprises the half-salt of a strong aromatic sulfonic acid such as toluene sulfonic acid and an imidazole, preferably an alkylated imidazole such as 2-ethyl-4-methylimidazole. The composition fully cures at moderate temperature to form a humidity resistant resin having a high heat distortion temperature and can be impregnated onto reinforcing fibers such as graphite to form composites.

Abstract: A high-strength, low weight, electromechanical cable is manufactured from aromatic polyamide multifilament yarns impregnated with a hydrolytically stable polyurethane resin to form a protective coating. The coating provides load adjustment from fiber to fiber, eliminates abrasive self-destruction of the fibers during flexing of the yarn under load, protects the fiber to some extent from ultraviolet radiation, aggressive chemicals or abrasive particles and makes it possible to preform the yarn. The coating comprises a reaction product of a liquid tetramethylene glycol, an aliphatic/cycloaliphatic diisocyanate and a diamine coupling-curing agent. The impregnated yarns are dried, twisted together, heated above the softening point of the resin to fuse the coatings of adjacent yarns, and then cooled to form a set twisted helix of the yarns.

Abstract: A low toxicity, castable, fast curing, polyurethane high strength elastomer is prepared from a liquid prepolymer diol, a cycloaliphatic diisocyanate, a polyalkanol amine and a small amount of soluble metal salt catalyst. The composition can be formulated by either a prepolymer or "one-shot" technique and cures at ambient temperature.

Abstract: A high-strength, low weight, electromechanical cable is disclosed. The cable is formed by polyamide multifilaments impregnated with a hydrolytically stable polyurethane to form a protective coating. The coating provides load adjustment from fiber to fiber, eliminates abrasive self-destruction of the fibers during flexing of the yarn under load, protects the fiber to some extent from ultraviolet radiation, aggressive chemicals or abrasive particles and makes it possible to preform the yarn. The coating comprises a reaction product of a liquid tetramethylene glycol, an aliphatic/cycloaliphatic diisocyanate and a diamine coupling-curing agent. The impregnated fibers are dried, twisted and then heated to the melting temperature of the coating.

Abstract: A coherent, adherent, thin coating for metal surfaces is disclosed. The coating comprises a polymeric composition of a high vinyl content, liquid, hydroxy-terminated butadiene prepolymer, chain extended and cured by polyisocyanates and polyamines. The coating is sprayed onto an aluminum surface and after evaporation of solvent and curing for a short period at elevated temperature exhibits an adhesion to aluminum of between 0.2 lb/in to 2 lb/in, an elongation of 75% to 150%, and a tensile strength from 1,000 to 4,000 psi. The coating is strippable when applied at 2-5 mil thickness onto aluminum, and protects the metal surface during etching in chromic acid, during high temperature bonding and during final assembly operations. The coated surfaces can be machined, riveted, drilled and stretch formed without any lifting or tearing of the coating.