Miscibility in blends of sulfonylated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) with homopolymers of halogen-substituted styrene derivatives

Abstract

Miscibility and phase behaviour in blends of poly( p-fluorostyrene) (PpFSt), poly( o-fluorostyrene) (PoFSt), poly( p-chlorostyrene) (PpClSt), poly( o-chlorostyrene) (PoClSt), poly( p-bromostyrene) (PpBrSt) and poly( o-bromostyrene) (PoBrSt) with partially sulfonylated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) copolymers [i.e. systems of the type ( A) n1 ( C 1− y D y ) n2 have been studied by d.s.c. as a function of temperature and degree of sulfonylation. For all the para-substituted styrene polymers/SPPO blends studied, limited miscibility regimes are found. A miscibility regime is also found for PoFSt/SPPO blends. However, PoClSt and PoBrSt are not miscible with any SPPO. Using the mean-field approach, we have calculated all the pertinent segmental interaction parameters for these blends. In several systems, certain blends have been found to exhibit lower critical solution temperature behaviour.