Preparation and characterization of hydroxyapatite/polycaprolacton-chitosan composites

To improve the mechanical property and the bioactivity of composites，the hydroxyapatite/polycaprolacton-chitosan (HA/PCL-CS) composites were prepared in a Hakke twin screw extruder . The composite (ω(HA) = 30%) was immersed in the simulated body solution and physiological saline to examine it s bioactivity and degradation respectively. The structure and component were characterized by scanning elect ron microscope (SEM)，X-ray diff raction (XRD) and Fourier transform infrared spect roscope (FTIR) . The results show that the tensile strength and fracture strain decrease with increasing of HA content，while the Young‘s modulus increases. The surfaces of HA/ PCL-CS composites are covered by a coating of carbonated hydroxyapatite (CHA) with low crystallinity，indicating the excellent bioactivity of the composites. After immersion in the physiological saline for 28d，the molecular mass decreases while pH and mass loss increase to 9. 54 and 5.86%，respectively，indicating a good biodegradation property of the composites.