Polyimides with pendent ethynyl groups

Abstract

Three novel diamines containing pendent ethynyl, hexynyl and phenylethynyl groups were synthesized and used to prepare polymers and copolymers. When heated to 250–350°C, the ethynyl groups react to form crosslinks. After curing, the homopolymers were brittle owing to the high crosslink density. Copolymers prepared using 10mol% ethynyl-containing diamine and 90mol% of diamines with no ethynyl groups were relatively tough, forming creasible films. After a thermal cure, the copolymers became insoluble and exhibited high T g values and good thin film properties.