The Effect of Poly Phosphate Salts and Nacconol on Tricalcium Phosphate Particle Size in Its Precipitation Process

TriCalcium Phosphate (TCP) is used as suspension stabilizer in styrene polymerization process. Particle size of TCP plays an essential role in the particle size, distribution and geometric form of polystyrene product. As the particle size of TCP is reduced, there will be much better chance to surround the styrene particle. The higher the number of TCP particles surrounding each styrene particle, the lesser will be their tendency to form a large particle after collision. Therefore the percentage of spherical polystyrene with small particle size and narrow distribution in the product are increased. In this study addition of polyphosphate salts and nacconol to the reaction mixture of TCP precipitation process and their effect on the particle size of TCP are investigated. The result show that addition of sodium hexa metaphosphate to the reaction mixture decreases the crystal growth rate and prevents precipitates to agglomerate. So the mean particles size of TCP is reduced from 5µm (without SHMP) to 1.5 µm (with SHMP).