A MEAN-FIELD TREATMENT OF THE INTERACTIONS IN BLENDS OF POLY(VINYL METHYL-ETHER) WITH POLY(STYRENE-CO-NITROSTYRENE)

A modification of the mean-field approach to polymer blends is described which allows the analysis of homopolymer-copolymer blends of the type A + CyD1-y in which the homopolymer is miscible with the copolymer between y = 1 (i.e., homopolymer C) and a single composition limit y = y1, where y1 > 0. The analysis utilizes the quadratic dependence of the blend interaction parameter (Bblend) on composition and equates the composition of the minimum value of Bblend to that of the maximum in the lower critical solution temperatures of the blends. Mixtures of poly(vinyl methyl ether) with poly(styrene-co-methyl methacrylate) and poly(styrene-co-m-nitrostyrene) are examined, and these yield a positive value for the styrene-vinyl ether interaction. © 1990, American Chemical Society. All rights reserved.