Studies Of The Preparation And Performance Of Hydroxyapatite/Polycaprolacton Composites

Hydroxyapatite (HA) is the main inorganic composition of bone tissue and is of good biocompatibility and high bioactivity, which makes HA be able to chemically bond to bone tissue. However, the brittleness and hard machining limit its extensive clinical use. Polycaprolacton (PCL) is biodegradable polyester with good have biocompatibility and high mechanical-physical properties. However, it lacks bioactivity. While the nature bone is mainly composed of nano-hydroxyapatite and collagen, it could be considered as a biphasic composite with nano-crystal. So, from a biomimetic perspective, a good bone substitute material would be obtained from the organic-polymer, especially degradable matrix, and hydroxyapatite phase, through simulation of human bone's structure. The composites combines the properties of the two materials, i.e., to carry their good properties forward and get rid of their shortcomings.The HA/PCL composites biomaterial were prepared through solvent-cast technique and melt-blend method with polycaprolactone matrix and nano-hydroxyapatite phase. The influence of compose and coupling agent on composites were discussed through studying the structure, component and mechanical properties of composites. The HA/PCL composites biomaterial were immersed in Simulated Body Solution (SBF) to examine its bioactivity.The experiment results indicated that HA and PCL exist with the form of crystalline in the composites. With addition of coupling agent, there isn't any remarkable interaction between the two phases. The examination of bioactivity in vivo shows that after immersed in SBF solution for 14d, the surface of HA/PCL(ω_HA=0.30) composites were covered with a coating of low crystalline CHA (Carbonated hydroxyapatite). It means that the composites prepared in the paper displayed well bioactivity. And the bioactivity increase with the content of HA. It seem that the bioactivity of composites were independent of the addition of coupling agent.The test of mechanical performance show that both of the fracture stress and fracture strain of the composites decrease with the content of HA. While the yield stress of...