INTERPOLYMER COMPLEXATION BETWEEN POLY(P-VINYLPHENOL) AND PYRIDINE-CONTAINING POLYMERS

Interpolymer complexation behavior between poly(p-vinylphenol) (PVPh) and three pyridine-containing polymers, poly(2-vinylpyridine) (P2VPy), poly(4-vinylpyridine) (P4VPy), and poly(2-vinylpyridine-co-styrene) (P2VPyS) with 70% vinylpyridine repeating units was studied. PVPh forms interpolymer complexes with the three pyridine-containing polymers over the whole feed composition range in ethanol solutions. The glass transition temperatures of the interpolymer complexes are remarkably higher than those calculated from the additivity rule, indicating strong favorable intermolecular interactions between unlike polymer chains. P2VPy has a stronger complexation ability with PVPh as compared with P2VPyS, showing the important role of pyridine group in achieving interpolymer complex formation. P4VPy shows a stronger complexation ability with PVPh as compared with P2VPy, demonstrating that the stereo-structure of repeating units affects interpolymer complex formation. When using N,N-dimethylformamide as solvent, complexation does not occur between PVPh and the three pyridine-containing polymers. Infrared studies of the complexes show the existence of hydrogen bonds between the phenolic hydroxyl groups and the nitrogens of pyridine groups, and the strength of interaction decreases in the order P4VPy > P2VPy < P2VPyS.