Effects of electron beam irradiations on the structure and mechanical properties of polycarbonate

Structure and mechanical properties of polycarbonate (PC) were investigated with varied electron beam processing parameters such as dose, dose rate and dose fractionation. PC showed noticeable decrease in ductility after doses of 100 kGy; a decrease in tensile strength is relatively minor. Molecular weight degradation was also noticed after 100 kGy. At 150 kGy and high dose rate (21 kGy/s), the tensile strength and ductility were evaluated against dose fractionation. It was found that tensile strength and ductility decreased with increasing number of passes, which resulted from longer cooling off times. The same temperature effect was observed with lower dose rate (1.2 kGy/s) when mechanical properties of irradiated samples were decreased significantly compared with samples irradiated with higher dose rate. No significant variation in molecular weight change was noticed in both cases.