Ion pair–ion pair and ion–dipole interactions in polyurethane–styrene blends

It is shown that ion pair–ion pair interactions can be utilized to achieve miscibility in blends of urethanes with styrene ionomers. The urethanes contain quaternary ammonium salts in the hard segments, while the styrenes contain sodium methacrylate groups (∼9.6 mol %). By contrast, ion–dipole interactions are not strong enough to achieve miscibility enhancement; a polyurethane containing short (ethylene oxide) sequences in the hard segment did not exhibit miscibility with a styrene–lithium methacrylate copolymer.