Abstract: This invention relates to the compositions and processes for preparing thermoset and thermoplastic polyimides derived from novel asymmetrical dianhydrides: specifically 2,3,3?,4? benzophenone dianhydride (a-BTDA), and 3,4?-(hexafluoroisopropylidene)diphthalic anhydride (a-6FDA). The a-BTDA anhydride is prepared by Suzuki coupling with catalysts from a mixed anhydride of 3,4-dimethylbenzoic acid or 2,3-dimethylbenzoic acid with 2,3-dimethylphenylboronic acid or 3,4-dimethylphenylboronic acid respectively, to form 2,3,3?,4?-tetramethylbenzophenone which is oxidized to form 2,3,3?,4?-benzophenonetetracarboxylic acid followed by cyclodehydration to obtain a-BTDA. The a-6FDA is prepared by nucleophilic triflouoromethylation of 2,3,3?,4?-tetramethylbenzophenone with trifluoromethyltrimethylsilane to form 3,4?-(trifluoromethylmethanol)-bis(o-xylene) which is converted to 3,4?-(hexafluoroisopropylidene-bis(o-xylene).

Abstract: Process for preparing polymer-reinforced silica aerogels which comprises a one-pot reaction of at least one alkoxy silane in the presence of effective amounts of a polymer precursor to obtain a silica reaction product, the reaction product is gelled and subsequently subjected to conditions that promotes polymerization of the precursor and then supercritically dried to obtain the polymer-reinforced monolithic silica aerogels.

Abstract: A deforming charge assembly is provided which has an inner and an outer cylinder formed from carbon fiber. Each of the inner and outer cylinders have an inner circumference surface having an inner diameter and an outer circumference surface having an outer diameter. The inner diameter of the outer cylinder is greater than the outer diameter of the inner cylinder. Each of the inner and outer cylinders have a first layer of circumferentially wound carbon fiber, a second layer of unidirectional carbon fiber sheet and a plurality of layers of carbon fibers circumferentially wrapped around the second layer. A plurality of sympathetic detonation barrier members are provided and have an inner surface in contact with the outer circumference surface of the inner cylinder and an outer surface in contact with the inner circumference surface of the outer cylinder.

Abstract: This invention is a non-fragmenting warhead casing prepared from at least one thermosetting epoxy resin and carbon fibers wherein the epoxy resin is characterized as a liquid, low viscosity resin at ambient temperatures, curable at temperatures ranging up to 175° F. and further characterized has having a glass transition temperature T(g) ranging from about 200° F. to 250° F.