The preparation and physical properties of polyester–poly(methyl methacrylates) triblock copolymers

Abstract

AbstractBlock copolymers having the basic structure of PMMA–PE–PMMA were prepared by the reaction of diisocyanate‐terminated polyesters with hydroxyl‐terminated poly(methyl methacrylate). The molecular weights of these copolymers varied from 7,500 to 47,000. The formation of block copolymers by this method was confirmed by infrared and molecular weight analyses as well as by the physical behavior of these materials. Block copolymers of molecular weight less than 21,000 were extremely brittle in nature. The stronger copolymers of molecular weight greater than 29,000 were examined as to their dynamic modulus and stress–strain behavior. This included the effect of added homopolymer on the stress‐strain behavior of such materials. To better understand their physical properties, the micelle theory of Inoue et al. was applied to these copolymers to help elucidate their morphologies.