Thermal and Flammability Characterization of Graphite Composites

Flammability, thermal, and selected mechanical properties of composites fabricated with epoxy and other thermally stable resin matrices are described. Properties which were measured included limiting-oxygen index, smoke evolu tion, thermal degradation products, total-heat release, heat-release rates, mass loss, flame spread, ignition resistance, thermogravimetric analysis and selected mechanical properties. This paper describes the properties of eight dif ferent graphite composite panels fabricated using four different resin matrices and two types of graphite reinforcement. The resin matrices included: XU71775/H795, a blend of vinylpolystyrylpyridine and bismaleimide; H795, a bismaleimide; Cycom 6162, a phenolic; and PSP 6022M, a polystyrylpyridine. The graphite fiber used was AS-4 in the form of either tape or fabric. The prop erties of these composites were compared with epoxy composites. It was deter mined that the blend of vinylpolystyrylpyridine and bismaleimide (XU71775/ H795) with the graphite tape was the optimum design giving the lowest heat release rate.