NMR characterization of intermolecular interactions for polymers, IV. Intermolecular interactions of low molecular weight analogues for compatible blends of polystyrene and poly(2,6‐dimethyl‐1,4‐phenylene oxide)

The intermolecular interaction, IMI, leading to the compatibility of polystyrene, PS, and poly (2,6‐dimethyl‐1,4‐phenylene oxide), PPO, has been identified by analyzing the IMI of the model compounds of low molecular weight; cumene, styrene oligomer, 2,6‐dimethyl phenol, and its trimer. The IMI has been detected and identified applying Rummens' method for the analysis of the solvent‐induced changes in NMR chemical shifts. The results indicate that the driving force in the formation of the compatible blend of PS and PPO is the π‐hydrogen bond between the electrodeficient methyl groups in PPO and π‐orbitals in PS. There were no indications that n ‐hydrogen bonds are formed between ring hydrogens of PS and the oxygen in PPO.