MORPHOLOGICAL, THERMAL, AND MECHANICAL-PROPERTIES OF POLYPROPYLENE POLYCARBONATE BLEND/

This work deals with the effect of compatibilizer on the morphological , thermal, rheological, and mechanical properties of polypropylene/pol ycarbonate (PP/ PC) blends. The blends, containing between 0 to 30 vol % of polycarbonate and a compatibilizer, were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting glyci dyl methacrylate (GMA) onto polypropylene in the molten state. Blend m orphologies were controlled by adding PP-g-GMA as compatibilizer durin g melt processing, thus changing dispersion and interfacial adhesion o f the polycarbonate phase. With PP-g-GMA, volume fractions increased f rom 2.5 to 20, and much finer dispersions of discrete polycarbonate ph ase with average domain sizes decreased from 35 to 3 mu m were obtaine d. The WAXD spectra showed that the crystal structure of neat PP was d ifferent from that in blends. The DSC results suggested that the degre e of crystallization of PP in blends decreased as PC content and compa tibilizer increased. The mechanical properties significantly changed a fter addition of PP-g-GMA. (C) 1997 John Wiley & Sons, Inc.