Resistance of UHMWPE to plastic deformation and wear and the possibility of its enhancement through modification by radiation

Abstract

Abstract The operational durability of a kinematical polymer–metal system, required in many applications, including endoprostheses used for the total knee or hip joint arthoplasty, depends largely on high resistance to wear and permanent deformation of the polymer cup, especially in its near‐surface layer, contacting with the metal part. In this study, the wear and deformation resistance of two ultra high molecular weight polyethylene (UHMWPE) grades used in arthoplasty, GUR1020 and GUR1050, as well as the possibilities of its enhancement by radiation treatment were studied in detail. An influence of the molecular characteristic of these grades on functional properties, including permanent plastic deformation, microhardness, elastic modulus, coefficient of the micromechanical wear were studied. The properties of GUR 1050 of higher molecular weight were found advantageous over GUR 1020 grade. It was also confirmed that irradiation with electron beam is an effective method of modification, resulting in an improvement of both resistance to permanent deformation and wear of UHMWPE. It was demonstrated that microhardness, Young's modulus, and wear resistance coefficient increase proportionally to the irradiation dose applied. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012