Hydrogen-bonding interactions between poly(styrene-co-methacrylic acid) and poly(styrene-co-4-vinylpyridine)

The complexation behavior between poly(styrene-co-methacrylic acid) of different compositions (SMA-12 or SMA-29) and poly(styrene-co-4-vinylpyridine) (S4VP-6 or S4VP-15) was studied by viscometry and differential scanning calorimetry using tetrahydrofuran (THF) and butan-2-one as solvents. This complexation is attributed to the presence of strong intermolecular interactions between the different polymer chains by hydrogen bonding. A single glass-transition temperature, intermediate between those of the two pure copolymers SMA-29 and S4VP-15, was obtained with each composition of the mixture when THF or butan-2-one is used as a common solvent. The obtained results showed that the formation of such complexes depends strongly on the nature of the solvent and the contents of the interacting species. The complex formation is inhibited in THF because of the important ability of this latter to interact with the SMA. A quantitative analysis of the interactions between the constituents of these blends was carried out by FTIR spectroscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 806–811, 2005