Preliminary Study On Preparation And Hydration Of Calcium Phosphate Cement

This paper mainly probed preparation process of tetra calcium phosphate [Ca₄(PO₄)₂O TTCP] that was the primary composition of CPC. In the CPC that consists of TTCP and dicalcium phosphate anhydrous (DCPA), TTCP has more important effect on CPC's properties, so it is necessary to probe its preparation. There are several factors that influence TTCP's properties. They are starting mixture of raw materials, molar calcium to phosphorous ratio, the solution used as dispersed medium during starting mixture is ground and mixed, firing temperature and firing time.First, investigated effects of different preparation processes on TTCP that were arranged some processing factors with orthogonal design. These factors were different starting mixture (dicalcium phosphate dihydrate plus calcium carbonate and tri-calcium phosphate (TCP) plus calcium carbonate), molar Ca to P ratio (1.9 and 2.0), different dispersed medium (distilled water and alcohol), different firing temperatures (1400℃ and 1450℃) and different firing time (10hours and 15 hours). Then these TTCPs which were synthesized in different processes, described above, were ground to similar size in the same grinding techniques and mixed with the same particle size DCPA to make into CPCs. Thereafter these CPCs were churned up at the same liquid/solid ratio and with the same setting liquid to make into compressive strength samples. Comparing with these samples' strength, TTCPs' capability were differentiated. Furthermore which process was better was known. And through analyzing the data the importance of every process factor to synthesis TTCP was also obtained. X-ray diffraction analyses were used to analyze transformation of phases during the preparations and setting reactions, and microcosmic morphology of TTCPs and CPCs' harden bodies were observed with scan electron microscope. The results show: 1.Starting mixture has the most important effect on TTCP. Using DCPA and calcium...