Structural and Composition of Natural Hydroxyapatite (HA) at Different Sintering Temperatures

Hydroxyapatite (HA) is one of the most attractive biomaterials and widely used as a bone substitute due to its compositions are similar to the minerals in teeth and bones. Understanding of natural HA properties are useful in order to produces high quality of HA. In this paper, we report an easy and low cost method to extract the natural HA from femur cow bone and subsequently sintered at different temperature from 900 degrees C to 1300 degrees C. Structural, composition and surface morphology of natural Hydroxyapatite (HA) at different sintering temperatures (900 degrees C, 1000 degrees C, 1100 degrees C, 1200 degrees C and 1300 degrees C) were discussed. The HA structural, composition and surface morphology were studied by using X-Ray Diffractometer (XRD), Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM), respectively. The results show the main HA phases were detected in the range of 31.72 degrees-31.82 degrees (2 theta) for all sintered HA corresponding to 211 plane. The crystallite size of HA increases with sintering temperature from 900 degrees C to 1100 degrees C. Spectrums of FTIR revealed the existences of functional groups of carbonate (CO32-), phosphate (PO43-) and hydroxyl (OH-) peaks. SEM micrographs presented small and homogenous grains from 900 degrees C to 1100 degrees C. The grains look interconnected as sintering temperature increased at 1200 degrees C and 1300 degrees C. From this study, sintering process was found to be an easy and low cost method to produce natural HA from femur cow bones.