No abstract

A processable, oxidatively stable polybenzothiazole (PBT) resin has been developed for use as a matrix in reinforced plastic struc tural composites subjected to elevated temperature. The complex chemistry of the resin polymerization reaction is presented. Composites using the new resin as matrix and Style 181 E glass cloth as reinforcement have been evaluated in flexure, tensile stress rupture and bending fatigue at temperatures ranging from ambient to 800°F. These composites have exhibited excellent retention of flexural properties after 300 hours heat aging at 600°F and six hours at 800°F in air. Bending fatigue and tensile stress rupture properties at 550°F are superior to those available from other high temperature resin composites, such as polyimides and polybenzimidazoles.