Blends of poly(α-methylstyrene-stat-acrylonitrile) with poly(alkyl acrylate)s, poly(alkyl methacrylate)s, poly(di-alkyl itaconate)s and alkyl methacrylate copolymers

The miscibility behaviour of the copolymer poly(a-methylstyrene-stat-acrylonitrile) (MSAN) with poly(alkyl acrylate)s, poly(alkyl methacrylate)s and poly(dialkyl itaconate)s has been investigated, where the alkyl groups were methyl, ethyl, n-propyl and n-butyl. Only in the poly(alkyl methacrylate) series were miscible blends obtained; no miscible systems were found for mixtures of MSAN with the other two sets of polymers. "Miscibility windows" were established for the MSAN-poly(alkyl methacrylate) blends and lower critical solution temperatures were also measured. From a knowledge of the phase boundaries, segmental interaction energy density parameters (B_ij) were calculated and used to make predictions about various copolymer-copolymer blends based on the appropriate monomers. These predictions were tested for blends of poly(a-methylstyrene-stat-acrylonitrile) and poly(methyl methacrylate-stat-acrylonitrile) and found to be very satisfactory. © 1992.