Synthesis and Characterization of Block Copolymers.

Polyether-Polyimide Block Copolymers Three series of Polyether-Polyimide PEPI block copolymers were synthesized. Soft segments were polypropylene glycol PPO Mn 2,000 and 4,000. Hard segments were pyromellitic dianhydride PMDA and di-2-hydroxyethyl-dimethylhydantoin H. The hard segments were formed from 4,4-diphenylmethane disocyanate MDI with PMDA or 95 PMDA and 5 H. The first series designated as PEPI-2K was synthesized with PPO-2,000, MDI and PMDA. The second series, PEPI-2KH, used PPO-2,000, MDI, 95 PMDA 5 H. The third series, PEPI-4K, used PPO-4,000, MDI and PMDA. PEPI copolymers in each series varied by weight percent of hard segment.