Stabilization of ethylene-propylene copolymer against gamma-ray induced degradation

Abstract

The post-irradiation storage stability of ethylene-propylene copolymer (CP) irradiated with gamma-ray at irradiation doses of 3 and 5 Mrad has been studied. The effectiveness of an antioxidant, two hindered amine light stabilizers and a nucleating agent in stabilizing ethylene-propylene copolymer against post-irradiation oxidative degradation, at various concentrations is compared with that of the control sample. The variation in melt index (MI), yellowness index (YI) and mechanical properties of stabilized CP was followed with respect to post-irradiation time. It is found that the HALS used for this study, do not contribute much towards the post-irradiation mechanical stability and result in higher discolouration, whereas the antioxidant and nucleating agent show a very good retention in the mechanical properties and less yellowing in the post-irradiation storage period. (C) 1998 . .