Biomechanical Properties of Dispersep Article Reinforced Polymer Composites on Ultrahigh Molecular Weight Polyethylene (UHMWPE)

Abstract

Biomechanical properties of composites based on UHMWPE and hybrid (polymer-polymeric) matrices “UHMWPE+PTFE” with disperse particle fillers were studied in order to develop materials for artificial joint implants. A comparative analysis of the efficiency on loading hydroxyapatite (HA) powder as biocompatible filler was performed. It was shown that wear rate of nano composites with the hybrid matrix is lower as compared with UHMWPE composites in conditions of dry friction and boundary lubrication. To optimize the composition of implant materials it is proposed to use the theory of dispersion hardening through the Mori-Tanaka model and Ilyushin function of plasticity as well as two-level method of computer-aided design. Comparison of calculation estimates by the developed technique with experimental data have shown that their relative error does not exceed 15%. Lowered values of the tensile strength of the nanoparticles filled composites is suggested to be due to lacking the interfacial layer consideration. Mechanical activation of powder components further enhances the durability of nano and micro composites almost doubling them without any substantial reduction in the strength properties. It is shown that wear resistance of nano- and micro composites with hybrid matrix under boundary lubrication is close to that at dry sliding friction.