The Effect of α-Tricalcium Phosphate Powder Preparation Methods on Cement Properties

The properties of calcium phosphate cements are influenced both by presence of setting aids in cement paste and also by surface properties and particle size distribution of solid phase. In this study the influence of α-tricalcium phosphate powder preparation methods on properties of cement are examined: milling, thermal treatment at temperatures up to 600°C and treatment with deionized water. The properties of cements based on prepared powders evaluated are: setting time, injectability and cohesion. The compressive strength of selected cement samples was determined. Thermal treatment improves injectability, but significantly prolongs setting time and reduces cohesiveness. Treatment of powder particles with deionized water increases setting time, but also significantly reduces injectability. It was not possible to significantly increase powder liquid ratio (from 1.75 to 2.00), if thermally treated powders were used. It was found that reduction of particle size, under certain conditions, can increase the injectability of cements. Powder preparation methods do not significantly affect the compression strength of cement, but fast setting upon the contact water based fluids is necessary to obtain cohesive cements.