Morphology investigation on high-pressure crystallized bisphenol-A polycarbonate/dioctyl phthalate blends

The high-pressure crystallized bisphenol-A polycarbonate/dioctyl phthalate (BAPC/DOP) blend samples were investigated using wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The specimens were prepared in a piston-cylinder high-pressure apparatus by varying the temperature, the pressure and the crystallization time for a BAPC/DOP (90/ 10, wt/wt) blend. The other four specimens were also prepared with different weight ratios of BAPC/DOR The DSC results showed that the amorphous BAPC could be crystallized in 45 min by the blending with DOP and the subsequent high-pressure treatment. A wide variety of morphologies of BAPC crystals were disclosed by SEM, including spherulites, spatial dendrites, crystalbars, platelets and regular polygonal crystals of different characteristics. The folded-chain lamellar crystals were found to be the substructures of these observed BAPC microstructures. The SEM revealed a granular substructure of the lamellae in a low-crystallinity sample as well, which indicated that the crystallization of BAPC in the multiphase system might possibly agree with the model developed by Strobl. (c) 2007 Wiley Periodicals, Inc.