Poly(phenylene)triazoles: New thermally stable fibers

Abstract

A chemical cyclocondensation reaction process has been developed to convert the easily prepared poly(phenylene)hydrazide to the corresponding high molecular weight poly‐3,5‐(m‐, p‐phenylene)‐4‐phenyl‐1,2,4‐triazole. Polytriazole fibers have been spun from formic acid solutions utilizing both wet and dry spinning techniques. These fibers develop a high degree of orientation and crystallinity on stretching at temperatures of 300°C. and higher. Such fibers retain approximately 30% of their initial breaking strength at a temperature of 300°C. and are not seriously degraded on exposure to elevated temperatures for prolonged periods. The fiber dimensional stability at temperatures above the glass transition temperature of 260°C. for the amorphous polymer was found to be directly related to the fiber orientation and crystallinity. The ease of fabrication and thermal stability of the phenylene triazole polymer makes this material potentially attractive for other end‐use applications such as films, protective coatings, and electrical insulation.