STUDIES ON MISCIBILITY OF POLY(PHENYLENE OXIDE)-BASED IONOMER POLYSTYRENE-BASED IONOMER BLENDS

The phase behavior of a series of blends obtained from mixing carboxyl ated poly(phenylene oxide) with sulfonated polystyrene and their respe ctive neutralized ionomers was studied by differential scanning calori metry. A substantially broader range of miscibility was observed when both blend components were functionalized, compared with blends in whi ch only one of the components contained an acid group or was an ionome r. The properties of metallic cations which were used to neutralize th e acid groups in the blends were found to have an effect on the miscib ility. The miscibility of the two acid polymers or their ionomers depe nded on the difference of their functionalization level instead of on the absolute percentage of functional groups on each polymer. It was f ound that the two acid polymers or their ionomers remained miscible as long as they had a similar percentage of functional groups. (C) 1997 John Wiley & Sons,Inc.