Abstract: Resins and carbon--carbon composites are formed from di(alken-1-yl) borinic acids and borinates, either as monomers or as nonpolymerizing additives in a monomer mixture, with the effect of sharply increasing the oxidative stability of the cured product. The compounds have the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.5 -C.sub.7 cycloalkenyl, aryl, (C.sub.1 -C.sub.6 alkyl)-substituted aryl, (C.sub.2 -C.sub.6 alkenyl)-substituted aryl, or (C.sub.2 -C.sub.6 alkynyl)-substituted aryl, at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being other than H.

Abstract: Resins and carbon-carbon composites are formed from di(alken-1-yl) borinic acids and borinates, either as monomers or as nonpolymerizing additives in a monomer mixture, with the effect of sharply increasing the oxidative stability of the cured product. The compounds have the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.5 -C.sub.7 cycloalkenyl, aryl, (C.sub.1 -C.sub.6 alkyl)-substituted aryl, (C.sub.2 -C.sub.6 alkenyl)-substituted aryl, or (C.sub.2 -C.sub.6 alkynyl)-substituted aryl, at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being other than H.

Abstract: Resins and carbon-carbon composites are formed from di(alken-1-yl) borinic acids and borinates, either as monomers or as nonpolymerizing additives in a monomer mixture, with the effect of sharply increasing the oxidative stability of the cured product. The compounds have the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.5 -C.sub.7 cycloalkenyl, aryl, (C.sub.1 -C.sub.6 alkyl)-substituted aryl, (C.sub.2 -C.sub.6 alkenyl)-substituted aryl, or (C.sub.2 -C.sub.6 alkynyl)-substituted aryl, at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being other than H.

Abstract: A novel polyphenylene resin is formed by the polycyclotrimerization of vinylethynylbenzene, diethynylbenzene and phenylacetylene. Polymerization is carried out under conditions which result in the retention of unreacted vinyl groups from the vinylethynylbenzene component, which are then susceptible to crosslinking. The polymer is useful in the formation of high-performance carbon-carbon composites, producing an unusually high char yield with advantageous handling and processing characteristics.

Abstract: Compounds having the formula ##STR1## in which R is a member selected from the group consisting of H, CH.sub.2 .dbd.CH--, and CH.tbd.C--, R' is a member selected from the group consisting of --CH.dbd.CH.sub.2 and --C.tbd.CH, and n is zero, 1, 2, 3 or 4, are useful as fluidizers for polyphenylene prepolymers, rendering the latter sufficiently fluid for processing to form high-performance carbonaceous materials. These compounds are also useful themselves as monomers and prepolymers for the formation of the high-performance carbonaceous materials.