Abstract: The high sublimation energy of industrial diamond pigment is combined with the clean ablation properties of an epoxy or urethane binder. The result is a low impulse decoy coating that has the desired compatibility with the decoy heat shield materials, good radar transmission, and a neutral effect on the electron densities in the wake. A high volume fraction of the diamond pigment is required to substantially reduce the blow-off impulse. The coating for a carbon-carbon substrate is a mixture of diamond pigment and a urethane or epoxy binder. Good quality, strong adherent coatings for a low-impulse decoy were fabricated in the range of 85 to 90 weight percent of diamond for both urethane and epoxy.

Abstract: Foamed cross-linked poly-N-arylenebinzimidazoles are prepared by mixing an organic tetraamine and an ortho substituted aromatic dicarboxylic acid anhydride in the presence of a blowing agent and then heating the prepolymer to a temperature sufficient to complete polymerization and foaming of the reactants. In another embodiment of the process, the reactants are heated to form a prepolymer. The prepolymer is then cured at higher temperatures to complete foaming and polymerization.