Preparation and characterization of hydroxyapatite/polycaprolactone-chitosan composites.

Hydroxyapatite (HA)/polycaprolactone (PCL)-chitosan (CS) composites were prepared by melt-blending. For the composites, the amount of HA was varied from 0% to 30% by weight. The morphology, structure and component of the composites were evaluated using environmental scanning electron microscope, X-ray diffraction and Fourier transform infrared spectroscope. The tensile properties were evaluated by tensile test. The bioactivity and degradation property were investigated after immersing in simulated body fluid (SBF) and physiological saline, respectively. The results show that the addition of HA to PCL-CS matrix tends to suppress the crystallization of PCL but improves the hydrophilicity. Adding HA to the composites decreases the tensile strength and elongation at break but increases the tensile modulus. After immersing in SBF for 14 days, the surface of HA/PCL-CS composites are covered by a coating of carbonated hydroxyapatite with low crystallinity, indicating the excellent bioactivity of the composites. Soaking in the physiological saline for 28 days, the molecular weight of PCL decreases while the mass loss of the composites and pH of physiological saline increase to 5.86% and 9.54, respectively, implying a good degradation property of the composites.