In the most recent type of highly cross-linked UHMWPE, stabilised by vitamin E, the majority of this anti-oxidant cannot be leached out. Even more, the vitamin E molecules are grafted to the UHMWPE polymer backbone by an ether bond. Today, highly cross-linked, vitamin E stabilised UHMWPE is clinically accepted as bearing material in joint replacements. Little is known about the chemistry of this antioxidant in the polymer after irradiation. The present investigation presents a model for the chemical nature of the trapping of vitamin E in PE.Summary Statement
Introduction