PHASE-BEHAVIOR IN COPOLYMER BLENDS OF PHENYLSULPHONYLATED POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) AND POLY(O-FLUOROSTYRENE-CO-P(O)-CHLOROSTYRENE)

Miscibility and phase behaviour in copolymer blends of partially pheny lsulphonylated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) with poly (o-Auorostyrene-co-p(o)-chlorostyrene) have been studied by differenti al scanning calorimetry at temperatures up to 573 K. It was found that miscibility depends on the copolymer compositions and the degree of s ulphonylation of the SPPO copolymers and on temperature. The width of the miscibility window in the blends containing copolymers with variou s p-chlorostyrene (pClSt) content and SPPO is much wider than in the c orresponding blends containing copolymers with o-chlorostyrene (oCISt) and SPPO. It was also found that sulphonylated segments of SPPO copol ymers enhanced miscibility in comparison with blends with poly(2,6-dim ethyl-1,4-phenylene oxide) (PPO). A qualitative account of these resul ts was obtained by using the segmental interaction parameters accordin g to the mean-field theory of phase behaviour.