Concepedia

Abstract

An alternating copolymer of N-methylmaleimide and isobutene was produced by a radical precipitation polymerization method. The copolymer thus produced is a new class of transparent polymeric material that shows a unique balance of optical, thermal, and mechanical properties. The visible light transmittance was more than 90% and the stress optical coefficient was smaller than that of polycarbonate, leading to moldings with lower birefringence. The heat deflection temperature of the copolymer was as high as 157°C, and the thermal expansion coefficient was about 30% smaller than those of poly(methyl methacrylate) and polycarbonate. The copolymer showed excellent mechanical properties, specifically, the flexural modulus was the highest among the typical amorphous polymers. © 1996 John Wiley & Sons, Inc.