Tricalcium phosphate powder: Preparation, characterization and compaction abilities

Abstract

In this work, we characterize tricalcium phosphate powders Ca9(HPO4)(PO4)5(OH) resulting from a reaction between calcium hydroxide and orthophosphoric acid at room temperature, without pH adjustment and in absence of ionic impurities. The prepared powder has an atomic ratio Ca/P of 1.512 ± 0.005. The real density is 2.68 ± 0.02 g/cm3 and the specific surface area is 80 ± 02 m2 /g. During compression, the microstructure of Cadeficient apatite powder with the presence of HPO4 groups seems to support the cohesion between particles. The transmission ratio is 90%, the transfer ratio is 41.8 and the ratio of the die-wall friction is 0.22. These results show that apatitic tricalcium powder gives a good aptitude to the compaction which leads to a good tensile strength (0.79 MPa). The heat treatment of the prepared powder shows the precise temperature for the formation of pyrophosphate, β-TCP and α-TCPa phases. The purity and aptitude to compaction of the prepared powders are very promising for pharmaceutical and medical applications.