Effect of gamma irradiation on polypropylene yarns under air and water

Polypropylene (PP) filters are used for the treatment of radioactive liquid waste containing gamma nuclides such as Co-60, and filter physical and chemical properties can be altered by means of γ-rays during the treatment process. In this study, irradiation tests were carried out to evaluate the effect of γ-ray on PP yarns under air and water condition. In the tensile test results, significant changes were observed when the absorbed dose exceeded 10 kGy. At the same time, the tensile strength and elongation at the break of irradiated yarns decreased with increasing absorbed doses, and showed great reductions under air condition compared to under water condition. Through the XPS results, it was confirmed that C–C bonds in PP yarn was radiolytically decomposed during irradiation, and this decomposition more actively progressed under air than under water.