INTERPOLYMER COMPLEXATION AND BLEND FORMATION BETWEEN POLY(N-VINYL-2-PYRROLIDONE) AND ALIPHATIC HYDROXYL-CONTAINING POLYMERS

The interpolymer complexation and blend formation between poly(N-vinyl-2-pyrrolidone) (PVP), a tertiary amide polymer, and three aliphatic hydroxyl-containing polymers, namely, poly(2-hydroxypropyl methacrylate), poly(hydroxyether of bisphenol-A) and poly(styrene-co-allyl alcohol), has been studied. PVP forms interpolymer complexes with all the three aliphatic hydroxyl-containing polymers in tetrahydrofuran solutions over the entire feed composition range. The glass transition temperatures of the complexes are higher than those calculated from the additivity rule. PVP has a stronger ability in forming interpolymer complexes with aliphatic hydroxyl-containing polymers than the other three tertiary amide polymers, namely, poly(N-methyl-N-vinylacetamide), poly(N,N-dimethylacrylamide), and poly(2-ethyl-2-oxazoline). Infrared spectroscopic studies show that the hydrogen bonding interactions between the carbonyl groups in PVP and the hydroxyl groups are stronger than the self-associations of the hydroxyl-containing polymers. Semiempirical Austin Model 1 (AM1) calculations reveal that the atomic charges of the carbonyl oxygen atoms of all these tertiary amide polymers are about the same, suggesting that steric factor is important in determining their complexation behavior.