POLYMERIC PRECURSOR ROUTE FOR THE PREPARATION OF CALCIUM-PHOSPHATE COMPOUNDS

A polymeric combustion synthesis is described for the preparation of c alcium phosphate compounds. The polymeric gel containing calcium and p hosphate ions were synthesised by concentrating a solution of calcium nitrate and ethyl phosphate. When the above gel was introduced to a fu rnace kept at 500 degrees C, a self combustion reaction was observed, leaving behind a calcium phosphate precursor powder. The above powder on heat treatment at 1000 degrees C resulted in beta-TCP, HAP or a mix ture of the two phases depending on the Ca/P ratio in the gel. Depende nce of Ca/P ratio on the composition of the calcium phosphate phase wa s studied by XRD. The morphological features of the precursor as well as the heat treated compounds were studied by SEM. The method offers a n easy route for the preparation of beta-TCP or HAP in the powder or i n the porous form. (C) 1998 Elsevier Science Limited and Techna S.r.l. All rights reserved.