The control of the texture in synthetic hydroxyapatite ceramics had limited their application in the ield of the materials for bone implantation, even more when it is used as a illing in cements and other formulations in orthopedic surgery. The present article shows preliminary results demonstrating the efectiveness of a modiication of the controlled rate thermal analysis (CRTA), developed by J. Rouquerol, used for the preparation of ceramic materials with controlled textural characteristics, during the formation of ceramic powders of synthetic hydroxyapatite at low temperatures. The thermal treatments of the hydroxyapatite were carried out in a device connected to a computer, to control temperature and pressure system, keeping the decomposition speed constant. Results, reported when preparing ceramic powders of hydroxyapatite at 300 and 850°C under controlled pressure, using synthetic hydroxyapatite with a Ca/P molar ratio equal to 1.64, were checked using IR spectroscopy and X-ray difraction, showed that the formed phase corresponds to that of crystalline hydroxyapatite, even at 300°C of maximum temperature. Values of speciic surface (BET) between 17 and 66 m 2 /g, with pore size in the range of 50-300 Å in both cases are obtained by N 2 absorption isotherms, when analyzing the isotherms of nitrogen absorption.

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