MORPHOLOGY AND PHASE-BEHAVIOR OF BLENDS OF A STYRENIC BLOCK-COPOLYMER IONOMER AND POLY(CAPROLACTONE)

The morphology and phase behavior of blends of a lightly sulfonated styrenic block copolymer ionomer and poly(caprolactone) (PCL) were investigated by small-angle X-ray scattering and differential scanning calorimetry. Miscibility of PCL in the ionomeric microphase was enhanced due to exothermic interactions between the sulfonate groups and the polyester. In the blends, PCL exhibited unique crystallization behavior due to the effects of miscibility and the restriction imposed by the microdomains. The addition of PCL also changed the microstructure of the block copolymer from a less ordered, elongated spherical morphology to a well-defined lamellar arrangement.