INTRAMOLECULAR INTERACTIONS IN POLY(STYRENE-CO-ACRYLONITRILE)/POLY(EPSILON-CAPROLACTONE)BLENDS

Specific interactions in blends of poly(epsilon-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) were studied as a function of copolymer composition and blend ratio by using Fourier-transform infrared spectroscopy (FTIR). It was shown that miscibility occurred within a certain range of copolymer compositions because the presence of PCL reduced the thermodynamically unfavorable repulsion between styrene and acrylonitrile segments in the random copolymer. This effect was observed in terms of a shift to higher frequencies in the 700 cm-1 gamma-CH out-of-plane deformation vibration absorption of styrene and in the approximately 2236 cm-1 C=N stretching frequency band in acrylonitrile segments. Specific intermolecular interactions between SAN and PCL were not observed in this study.