Effect of microcrystallinity on the mechanical performance of polycarbonate

Samples of polycarbonate (PC) before and after remelting and isothermal sol idification treatment were characterized by wide-angle X-ray scattering (WA XS) and small-angle X-ray scattering (SAXS), microhardness, and stretching calorimetry techniques. Both PC samples could be regarded as structurally i dentical (X-ray amorphous); however, the isothermally solidified sample exh ibited higher microhardness and Young's modulus, as well as a lower linear expansion coefficient and greatly reduced breaking strain. These results ar e attributed to the overlap of a network of ultramicrocrystals on the origi nal entanglement network in the reference (untreated) PC sample,