NMR and dynamic mechanical studies of miscibility enhancement via ionic interactions in polystyrene/poly (ethyl acrylate) blends

Abstract Direct ion‐ion interactions in ionomer blends are achieved through microion elimination by mixing the two ionomers, poly (styrene ‐co‐tetraalkylammonium methacrylate) and poly (ethyl acrylate‐co‐Nmethyl‐4‐vinyl pyridinium. iodide), in a benzene/ methanol mixture. The pyridiniumcarboxylate ionion interactions are compared with pyridinium‐sulfonate interactions which were described before. It is shown that carboxylate ions are much less effective than sulfonate ions in enhancing miscibility in the polystyrene/ poly (ethyl acrylate) system. Complete miscibility is not attained for this polymer pair even with up to 10 mol % ions. In another system, ion pair‐ion pair blends were prepared by mixing poly (styrene‐co‐sodium styrenesulfonate) with poly (ethyl acrylateco‐N‐methyl‐4‐vinyl pyridinium iodide), also in a benzene/ methanol mixture. The results show that ion pair‐ion pair associations are also a much weaker driving force for miscibility enhancement in this polymer pair than the corresponding direct pyridinium‐sulfonate ion‐ion interactions. A ranking is presented of the relative strengths of the various ionic interactions in their effect on miscibility enhancement, which also includes ion‐dipole interactions (sodium sulfonate‐pyridine).