Processing and Mechanical Characterization of Compression-Molded Ultrahigh Molecular Weight Polyethylene Biocomposite Reinforced with Aluminum Oxide

Abstract

Ultrahigh molecular weight polyethylene (UHMWPE) has been widely used as a bone implant material in orthopedic surgical applications in trauma due to its low coefficient of friction, good biocompatibility, and excellent wear and corrosion resistance properties in comparison to other polyolefins. But, due to the formation of wear debris, implants loosen and fail after 12–15 years of implantation. In order to enhance lifespan, the role of alumina (Al2O3) reinforcement on the mechanical properties (like hardness, elastic modulus, etc.) of compression-molded UHMWPE biocomposites is evaluated. The phase characterization (performed using X-ray diffraction and FT-IR spectroscopy) of starting raw materials and composites elicited retention of starting phases in the blended powders as well as compression-molded composites. Differential scanning calorimetry analysis exhibited increases in crystallinity with alumina reinforcement by (~18%), though a ~39% improvement in the Vickers hardness was observed, when compared to that of virgin UHMWPE. The mechanical characterization showed an increase in modulus by ~6%, decrease in the tensile strength by ~20% and strain to failure from 501.63 to 486.17% with Al2O3 reinforcement. The fracture surface of tensile-tested samples showed the cyclic stress failure under tensile stress.

Keywords: UHMWPE, MWCNTs, tensile properties, differential scanning calorimetry (DSC)