EFFECT OF PHOTOCHEMICAL AGING ON THE TENSILE PROPERTIES AND BEHAVIOR LAW OF UNSTABILIZED FILMS OF LOW-DENSITY POLYETHYLENE

Films of low-density polyethylene (LDPE) were exposed to artificial ag eing in a photochemical reactor, and photochemical ageing was observed by tensile measurements. Oxidative degradation was characterized from carbonyl groups formation using infrared spectroscopy. Only ultimate properties seem to be affected, elastic properties being practically u naffected. In fact, the most obvious chemical effect induced in LDPE b y exposure is the formation of carbonyl groups easily observable by in frared spectroscopy. Some elementary acts of the oxidation process ind uce chain scissions responsible for the decrease of elongation at brea k.