Benhong Yang, Meng Li, Yun Wu, Jianjiang Huang, Hui Zhang, Chonghai Deng
November 30, 2012
A series of hydroxyapatite (HAp)/poly(methyl mathacrylate) (PMMA) nanocomposites were prepared by free radical copolymerization of surface-modified HAp with methyl mathacrylate (MMA) via a bulk copolymerization process. Fourier transform infrared spectrophotometry and X-ray diffraction were employed to characterize the structures of the HAp/PMMA nanocomposites. Scanning electron microscope images showed that the as-prepared composite films were smooth, and no severe aggregation of HAp was observed when HAp content was <10 wt%. Thermogravimetric analysis and differential scanning calorimetry results indicated that the incorporation of a suitable amount of nanosized HAp enhanced the thermal and mechanical properties of PMMA. When 20 wt% of HAp was incorporated into the PMMA matrix, the glass-transition temperature, thermal degradation temperature and tensile strength increased by 13°C, 52°C and 76.2%, respectively, compared to the mother PMMA. However, higher HAp contents (>20 wt%) weakened the thermal and mechanical properties of the nanocomposites owing to the phase separation in the composite matrix caused by the strong aggregation of HAp particles.