Fourier Transform Infrared Studies of Polymer Blends. 6. Further Observations on the Poly(bisphenol A carbonate)-Poly(e-caprolactone) System

Preliminary Fourier transform infrared (FT IR) studies of poly(bisphenol A carbonate) (PC)-poly(ε-caprolactone) (PCL) polymer blends have been reported elsewhere. In this publication we present further results pertaining to this gordian polymer blend system. Blends of PC and PCL are compatible in the amorphous state and both polymers are capable of crystallization. Not only is the state of order of the two polymeric components in the blend a function of composition and temperature but it is also markedly dependent upon the method of film preparation. FT IR spectroscopy has been employed to study the variation of crystallinity of both components in the blend from films cast from different solvents and at different evaporation rates. The effect of exposure to acetone vapor of the polymer blend films has also been studied. Additionally, attempts have been made to obtain information concerning the origin, type, and relative strengths of polymer-solvent interactions from solution FT IR studies of PC in a variety of solvents. Finally, stepwise temperature studies of the PC-PCL blends have been performed. Polymer-induced crystallization of PC is readily observed and the results are considered in terms of the predicted Tg of the amorphous phase. The melting point of PCL in the blends may also be determined. Implications concerning the polymer-polymer interaction parameter are discussed.