A Research On Preparation And Degradation Properties Of The Composites Based On ?-TCP

Beta-TCP is one kind of most promising bone repair materials for its good properties of biocompatibility, osteoinductivity and osteoconductive. But it is relatively stable in neutral or alkaline environment, and of slow degradation. And other ceramic materials and polymers such as UPPE have excellent degradation property. If composition with the beta-TCP, it's able to adjust the degradation property of the materials. So this article was aimed at systemly studying on the preparation and degradation performance of the composite material based on beta-TCP.The experimental result of precipitation and hydrothermal preparation of the beta-TCP powder showed that When the Ca/P was near to 1.5 and the calcination temperature was above 800?, more pure beta-TCP could be got. And the lower the calcination temperature was, the smaller the particle size of the powder was. Hydrothermal method is not suitable for the preparation of single phase beta-TCP powder, but for the preparation of beta-TCP/HA duplex ceramic powder. Improving the hydrothermal temperature or prolonging the hydrothermal time can improve the content of HA in composite material of beta-TCP/HA. Ca/Mg/PO4 composite doped with Mg was got by chemical coprecipitation preparation. And XRD said it was mainly composed of beta-TCP and Ca4Mg5(PO4)6 phases. And the more Mg was used, the more Ca4Mg5(PO4)6 in composite was. Beta-TCP/UPPE composites were prepared by gel casting. SEM showed that Beta-TCP was coated by UPPE when UPPE was more.The beta-TCP, Ca/Mg/PO4 composites, beta-TCP/UPPE composites was immersed in simulated body fluid to study their degradation property. It showed that single-phase beta-TCP material was degraded slower. The size of the particles on the surface was smaller and smaller, but quality of the material was more and more. Its degradation mechanism was: the calcium phosphate ions was dissolved from beta-TCP, and then precipitated in the form of HA and beta-Ca3(PO4)2. In the whole process, the precipitation rate was greater than the dissolution rate. But the Ca/Mg/PO4 composite degraded rapidly and the mass loss was about 2% in 30 days. Among it, the Ca4Mg5(PO4)6 dissolved faster, and made the dissolution rate of calcium phosphate ion accelerated.And t he degradation rate of the beta-TCP/UPPE composite increased significantly. The mass loss was 15% ~ 35% within 30 days. Its degradation mechanism was: the UPPE was degraded rapidly and the acidic materials could promote the degradation of the beta-TCP, such making the release of calcium phosphate ions accelerated. In the process of degradation of the three kinds of materials, the phase compositions were relatively stable, but a small amount of HA appeared on material's surface, and the HA may hinder the further degradation of material, but the effect was not big.