Friction, wear, and tensile properties of vacuum hot pressing crosslinked UHMWPE/nano-HAP composites.

Abstract

Ultra high molecular weight polyethylene (UHMWPE) is a thermoplastic engineering plastic with excellent mechanical properties. In this study, nonirradiated and irradiated UHMWPE/nano-hydroxyapatite (nano-HAP) composites were prepared by vacuum hot-pressing method, and then friction, wear, and tensile properties were investigated. To explore mechanisms of these properties, differential scanning calorimetry, infrared spectrum, and scanning electron microscopy with energy dispersive spectrometry analysis were carried out on the samples. The results in this study indicated that reduced friction coefficients and wear rate could be obtained when nonirradiated and irradiated UHMWPE were filled with 7% nano-HAP. The irradiated UHMWPE/7% nano-HAP also had a synergistic function of wear reduction as compared with irradiated UHMWPE and nonirradiated UHMWPE/7% nano-HAP. Samples filled with 7% nano-HAP showed a brittle fracture behavior, and a linear relationship between modulus and crystallinity for a nonirradiated and irradiated sample was found in this study.