Effects of gamma irradiation on antioxidants and ultraviolet stabilizers

The effects of gamma irradiation on18kinds of antioxidants and 10 kinds of ultraviolet stabilizers, intact or in a polyethylene sheet, were studied. After irradiating at a 30kGy dose, the content of additives themselves did not change and new degradation products were not found. While most antioxidants in polyethylene had a decreased content after irradiation, most ultraviolet stabilizers didnot change. During the migration tests with aqueous food simulants, additives were not released from either irradiated or unirradiated sheets. For the migrationtests with n-heptane, however, all additives were released from the unirradiated sheet, while most of the antioxidants were not released or released only slightly.