Oxidation resistance and abrasive wear resistance of vitamin E stabilized radiation crosslinked ultra-high molecular weight polyethylene

The effect of gamma radiation on the oxidation and wear resistance of ultra-high molecular weight polyethylene (UHMWPE) has been extensively studied since these properties are critical for the longevity of UHMWPE components of total joint replacement prostheses. While gamma radiation increases wear resistance of UHMWPE, the free radical generated in the lamellar regions by radiation must be stabilized before oxidative degradation occurs as the polymer ages. Initially, post-radiation melting conducted to quench free radicals but this treatment also decreases its mechanical properties. Recently, it has been replaced by incorporation of Vitamin E into UHMWPE to combat oxidative degradation. In this study, we assessed wear resistance of Vitamin E stabilized UHMWPE under abrasive wear conditions and oxidation resistance by shelf-aging irradiated components for 2 years. Equilibrium swelling experiments showed that Vitamin E decreased crosslink density, which affected wear resistance, but oxidation resistance was better preserved with increasing concentration of Vitamin E. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44125.