Synthesis of p-Calcium Pyrophosphate by sol-gel method

摘要

Beta calcium pyrophosphate [P-CPP, p-Ca2P2O7] can be used as bone graft extender in posterolateral lumbar fusion. In this research, p-CPP was synthesized by sol-gel method using phosphorus pentaoxide [P2O5] and calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] as phosphorus and calcium precursors. The reaction was carried out in ethanol medium with Ca/P ratio of 1.67. After 21 hours of reaction and 20 hours of drying at 80°C, white powder of amorphous calcium phosphate (ACP) was produced. Transformation of ACP to P-CPP was undertaken by fining at 400-800°C for 8 hours. Transformations of amorphous to microcrystalline, semicrystalline and crystalline structures occur at 400, 600 and 800°C, respectively. The P-CPP with the crystallite size of 61.71 nm, Ca/P ratio of 0.89 and Ca/O ratio of 0.21 was achieved by firing at 800°C. Morphology changes due to firing in which irregular shape of P-CPP at 400° changed to regular cuboid at 600 °C and above.