Mirtchi A A, Lemaître J, Munting E
Université Catholique de Louvain, Unité de Chimie des Interfaces, Belgium.
Biomaterials. 1990 Mar;11(2):83-8.
The setting and strengthening properties of beta-tricalcium phosphate (beta-TCP)--dicalcium phosphate dihydrate (DCPD)--calcite blends upon admixture with water were investigated at 25 and 37 degrees C. Setting was accelerated by seeding the system with hydroxyapatite (HAp), and strengthening improved when the solids were mixed with a solution saturated with DCPD and HAp. The relationship strength versus ageing time in wet conditions was correlated with mineralogical changes of the material. X-Ray diffraction, thermal analysis and scanning electron microscopy observations showed that DCPD and calcite react together to form small HAp crystals acting as bridges between the beta-TCP aggregates present in the paste. Both gaseous CO2 released by the reaction of calcite and the conversion of lower (DCPD, calcite) to higher-density phases (HAp) contributed to increase the porosity of the material. Nevertheless, quite acceptable diametral strengths (around 1.5 MPa) could be achieved, despite the high porosity of the hardened product (up to 54 vol%). After exhaustion of DCPD, calcite can react with beta-TCP to form further HAp, but this process is detrimental to the strength of the material. Both the mineralogical transformations, and the strengthening of the material were accelerated considerably upon increasing the ageing temperature.
在25摄氏度和37摄氏度下，研究了β-磷酸三钙（β-TCP）-二水磷酸二钙（DCPD）-方解石混合物与水混合后的凝结和增强性能。通过用羟基磷灰石（HAp）晶种引发体系来加速凝结，当固体与饱和DCPD和HAp的溶液混合时增强效果得到改善。材料在潮湿条件下的强度与老化时间的关系与材料的矿物学变化相关。X射线衍射、热分析和扫描电子显微镜观察表明，DCPD和方解石共同反应形成小的HAp晶体，这些晶体充当糊剂中存在的β-TCP聚集体之间的桥梁。方解石反应释放的气态二氧化碳以及较低密度相（DCPD、方解石）向较高密度相（HAp）的转变都导致材料孔隙率增加。然而，尽管硬化产物的孔隙率很高（高达54体积%），仍可获得相当可观的径向强度（约1.
