Characterization of ultra-high-molecular-weight polyethylene (UHMWPE) modified by ion implantation

Abstract

Surface modification of ultra high molecular weight polyethylene (UHMWPE) is induced by ion implantation of different ions at 300 keV energy. The aim of this work was the chemical, physical and mechanical characterization of the modified material in order to know deep inside about the effect of the ion beam upon the polymer. The irradiated surfaces are investigated by Raman spectroscopy, infrared absorption and micro-hardness analysis, scanning electron microscopy. Pin on disc measurements valuated the wear of the UHMWPE against a stainless steel probe; wear resistance increases of about 76% after the ion implantation. This result can be attributed to the ion bombardment inducing a micro-hardness increasing in the irradiated layers due to the high carbon surface concentration and cross-linking effects in the polymeric chains. The irradiated UHMWPE surfaces may find special applications to the field of the mobile prosthesis.