Abstract: Resin compositions are provided which are used in combination with fibers to form self-adhesive prepreg sheets that are applied to core materials to form sandwich panels. The prepreg resin includes a thermoset resin, a curing agent and a viscosity control agent. The prepreg resin further includes certain thermoplastic particles which are used to control the flow characteristics of the prepreg resin and the formation of fillets during bonding of the prepreg to the core material.

Abstract: Electrically conductive polymeric compositions suitable for fabricating devices for safely transporting volatile chemicals and fuels are disclosed. The electrically conductive polymeric compositions include at least one matrix polymer and an electrically conductive filler material incorporated in the matrix polymer in an amount sufficient to provide the conductive polymeric composition with an electrical conductivity of at least 10.sup.-10 S/cm. The electrically conductive filler material is intrinsically conductive polymer coated carbon black particles. The coating of intrinsically electrically conductive polymer provides a protective shield against loss of particle conductivity, contributes to the overall conductivity of the filler material and enhances the mechanical properties of the filled matrix polymer.

Abstract: Thermoplastics containing imide groups in the polymer backbone, soluble in an unmodified state, are rendered reactive with thermosetting resins by partial conversion of the polymer backbone to provide reactive groups. The modified polymer may be added as microspheres to a thermosetting resin, subsequently crosslinking therewith supressing solvent sensitivity in a fiber reinforced matrix composite comprising the toughened resin as the matrix therefore. The modified polymer microspheres retain their physical identity in the cured composite structure.

Abstract: Polyethersulfone is densified by preparation of a homogeneous paste with a semi-solvent, which may be drawn off by heating and vacuum, from an emulsion prepared from the paste. The resulting PES is substantially densified, with a reduced surface area. The densified PES can be added in significant amounts to thermosetting resin preparations, without a substantial increase in of viscosity.

Abstract: Stabilized, catalyzed polyurethane systems are disclosed which are comprised of a polyurethane prepolymer, a tertiary amine catalyst and a stabilizing agent. To extend shelf life, and lend stability to the composition, the stabilizing agent is comprised of methane sulfonic acid. The stabilizer is suitable for use with most polyurethane systems catalyzed by tertiary amines, and produces longer shelf life or stability with lesser amounts than conventional stabilizers.In a particular embodiment requiring extended shelf life but quick curing times, a catalyst yielding these qualities is bis(2,6-dimethylmorpholino)diethylether. The catalyst, when incorporated in a polyurethane prepolymer coated on a flexible substrate, can be immersed in water, the material thereafter being wrapped about the portion of the patient's body to be immobilized, and cures rapidly, within about 15 minutes. The catalyst can optionally be combined with a stabilizer, such as methane sulfonic acid.