Stduy on Mechanical Properties of Perlite-Filled Gamma-Irradiated Polypropylene

摘要

This study covers the preparation and characterization of perlite-filled polypropylene (PP). The compositions of 15, 30, and 50 % by weight perlite-PP com-posites were prepared by melt-mixing. The PP used in this study was either applied in the virgin form or #gamma#-irradiated in air at the doses of 10, 25, 50, and 100 kGy to determine the effect of oxidative degradation in composite properties. Furthermore, the active sites containing oxygen produced by #gamma#-irradiation in PP may provide a possible en-hancement by the interfacial interaction between perlite and PP. An initial sharp drop in torque readings during the melt-mixing of perlite-PP composite preparation indi-cated an extensive chain scission and degradation by #gamma#-irradiation. The thermal prop-erties of the composites were characterized by DSC. The ultimate tensile strength and elongation and also impact strength decreased in all composites with #gamma#-irradiation. Yet, these changes appeared not to be faster than was the change in unfilled PP upon irradiation. Scanning electron microscopy revealed an interfacial adhesion between perlite and irradiated PP while virgin PP did not show any evidence of adhesion.