Polycarbonate effects on selected mechanical properties of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) binary blending systems

Two polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) binary systems of different blend ratios were prepared in a twin screw extruder. The two ABS (PA-747 and PA-757) differed from each other largely by their flowability (as reflected by their different melt flow rates). Results of the selected mechanical properties tests suggested that the PC/ABS-757 system was generally more superior to the PC/ABS-747 system. It was also shown that the impact toughness of the two PC/ABS systems increased with increasing PC content. As compared to PC/ABS-757, the impact toughness of PC/ABS-747 was found to be greater than that of PC/ABC-757 only at PC content less than 40%, beyond which, it was actually lower. The micrographs obtained from the SEM analysis revealed that the nonuniformity of the domains formed by the dispersed phase was found to be responsible for the low impact toughness at a low PC content level. The overall performance of the two blending systems suggested that blending PC into PA-747 appeared to have insignificant benefit. On the other hand. addition of PC into PA-757 was found to have some synergetic effects. Furthermore, some of the selected mechanical properties performance exhibited by the PC/ABS-757 system were found to be well described by the additivity mixing rule.