J-integral fracture toughness, Tearing modulus and tensile properties of Vitamin E stabilized radiation crosslinked UHMWPE.

Abstract

Radiation crosslinking of ultra-high molecular weight polyethylene (UHMWPE) increases its wear resistance in total joint replacement prostheses. Unfortunately, it is accompanied by a dose-dependent decrease in several mechanical properties. In this study, the tensile properties and fracture behavior of radiation crosslinked, Vitamin E stabilized UHMWPE was studied as a function of radiation dose. The Rice and Sorensen model, applicable to elastic-plastic materials, was utilized to obtain the initial crack driving force, J1c, steady state J-integral fracture toughness, Jss and the Tearing modulus. Tensile tests showed the dependence of tensile properties on radiation dose. Jss of non-crosslinked UHMWPE was higher than for crosslinked UHMWPE׳s but there was no dose dependent change in Jss whereas there was almost no change in J1c over the entire dose range. Finally, a monotonic decrease in Tearing modulus was observed with radiation dose.