ИСТИНА

The main goal of this work was the synthesis of amorphous precursors for the biphasic ceramic with pre-determined Ca/P ratio between 0.5 and 1.5. In the course of the work we developed several routs of condensed ammonium phosphate synthesis for subsequent precursor obtainment and, finally, fabricated biphasic ceramics through thermal treatment of the precursors. In the present work ammonium phosphates were synthesized by various methods with the help of ion-exchange resins and phosphates of nitrogen-containing organic bases. At the next step we obtained amorphous chemically mixed anionic precipitates by co-precipitation. Synthesis of the precursor was performed by pouring solution of calcium nitrate to solution of several condensed ammonium phosphates. The calcination of the precursor led to the formation of biphasic ceramic material characterized by submicron grain size. As a result, we have produced a number of precursors for biphasic ceramics based on resorbable calcium phosphates with pre-determined Ca/P ratio. Obtained condensed ammonium phosphates were proved to be pure individual substances by XRD. The main aspects of sintering, microstructure and quality of the obtained material and amorphous precursors were analyzed by XRD, scanning electron microscopy, thermal analysis and mechanical tests. Thus, we can regulate composition of the ceramics at the stage of precursor synthesis and create the whole range of materials with variable Ca/P ratio and tunable properties.