THE SYNTHESIS OF POLY(STYRENE-CO-SODIUM STYRENE-PARA-CARBOXYLATE)

This article describes a technique for the homogeneous lithiation and subsequent carboxylation of high-molecular-weight polystyrenes containing up to 14 mol % p-bromostyrene. Thus, poly(styrene-co-p-bromostyrene)s were reacted in dilute tetrahydrofuran solution with large stoichiometric excesses of n-butyllithium with no precipitation of ionomer and subsequently carboxylated with anhydrous carbon dioxide or dry ice. By this technique polystyrenes in which up to 100% of the original bromine groups had been replaced by carboxyl functionalities were obtained.