An investigation of the compatibility and morphology of semicrystalline poly(ε‐caprolactone)–poly(vinyl chloride) blends

Blends of poly(ε‐caprolactone) (PCL) and poly(vinyl chloride) (PVC) were investigated at concentrations of PCL greater than 50 wt % using purified materials. For these concentrations, PCL partially crystallizes with degrees of crystallinity ranging from 50% for pure PCL to < 10% for the 50% mixture. Small‐angle x‐ray scattering was used to characterize the resultant morphologies. Model calculations for the interference functions and for the integrated scattering indicate that PVC is incorporated between the PCL lamellae and that the two polymers form a homogeneous mixture in the amorphous phase. These results were compared to previous results on the same system using the identical technique. Purification of the two homopolymers proved to play a critical role in the overall mixing characteristics of PVC and PCL