CHEMILUMINESCENCE STUDIES OF RADIATION-INDUCED OXIDATION OF VARIOUS POLYETHYLENES

The chemiluminescence (CL) emission from three kinds of polyethylene, HDPE, LLDPE and LDPE, which had been exposed to 80 kGy dose from Co-60 in both air and nitrogen, has been examined. CL measurement was done under both nitrogen and oxygen atmosphere. The results show that the C L emission from irradiated samples does not result from irradiation it self, but from the oxidation reactions occurring during and after irra diation. Addition of 1 phr of an antioxidant, Irganox 1010, can effect ively inhibit the radiation induced oxidation in LLDPE and LDPE. In th e case of HDPE, however, it was found that pure HDPE has the best resi stance to radiation-induced oxidation of the polymers examined in this work. However, incorporation of Irganox 1010 was found to have not on ly a stabilizing effect against radiation induced oxidation, but also to promote the oxidation in some cases.