Blends of poly(styrene-ran-2,4-dinitrostyrene) with poly(vinyl methyl ether) and poly(2,6-dimethyl-1,4-phenylene oxide)

Phase boundaries and lower critical solution temperatures for blends of random styrene-dinitrostyrene copolymers with poly(vinyl methyl ether) and with poly(2,6-dimethyl-1,4-phenylene oxide) have been established. From an analysis of phase behaviour in terms of the overall blend interaction energy density the relevant segmental interaction energy densities have been evaluated and these have been compared with the corresponding energy densities for mononitrated copolymers. It was concluded that nitro group substitution has an adverse effect on mixing with poly(vinyl methyl ether) despite its electron withdrawing capabilities, and causes a similar effect in poly(2,6-dimethyl-1,4-phenylene oxide) mixtures for primarily structural reasons. (C) 1997 Elsevier Science Ltd.