SMALL-ANGLE SCATTERING INVESTIGATIONS OF POLY(EPSILON-CAPROLACTONE) POLYCARBONATE BLENDS .2. SMALL-ANGLE X-RAY AND LIGHT-SCATTERING STUDY OF SEMICRYSTALLINE SEMICRYSTALLINE AND SEMICRYSTALLINE AMORPHOUS BLEND MORPHOLOGIES

Crystalline morphologies of poly(epsilon-caprolactone) (PCL) and polyc arbonate (PC) blends were probed with small-angle X-ray scattering (SA XS) and small-angle light scattering (SALS). Quantitative SAXS analysi s suggested that random mixing of PCL and PC lamellae occurred in the semicrystalline/semicrystalline state. Two distinct regions of incorpo ration were identified in the semicrystalline/amorphous state. It was found that PCL was rejected from the PC interlamellar region in the PC L-rich blends. In contrast, PCL was incorporated into the amorphous ph ase between the crystalline lamellae in the PC-rich blends. This trans ition from interlamellar exclusion to interlamellar inclusion may be r elated to the glass transition temperatures or the mobility of the ble nds. It is proposed that the mode of incorporation or exclusion is gov erned by the competition between entropy and diffusion. Additionally, SALS coupled with optical microscopy indicated that PC is an effective nucleating agent for PCL crystallization as manifested by the reducti on of PCL spherulitic size with the addition of PC.