Effects of blend composition on the morphologies and physical properties of polycarbonate/acrylonitrile-butadiene-styrene blends

The morphologies and physical properties of twin-screw-extruded polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends with various blend ratios are studied. The needle-like co-continuous phase in PC-rich blends changes to the sea-island phase for blend ratios of more than 50 wt% ABS. While pure PC exhibits an almost-Newtonian flow behavior, PC/ABS blends exhibit the interesting rheological transition. The viscosities of the ABS-rich blends at low shear rates are almost equal to those of the pure ABS polymer. The yield stress for the PC/ABS blend ratio of 3:7 is the highest in composition. At the frequency of 10 rad/s, the PC-rich blends exhibit highly viscous properties, whereas the ABS-rich blends present highly elastic properties as the temperature increases. Moreover, the ABS polymer in the PC/ABS polymer blend induces significant change at the fracture surface of PC, transitioning from brittle to ductile nature.