Control of -Tricalcium Phosphate Formation in Macroporous Phosphate Glass-Ceramic Composites

A macroporous phosphate invert glass-ceramic (PIGC) was derived from the mother glass with a composition of 60CaO-30P2O5-3TiO27Na2O in mol%. The mother glass powders were coated on a polymer sponge skeleton and subsequently sintered at 850 C for 1 h through burning off the sponge, resulting in the preparation of macroporous PIGC. The resulting macroporous PIGC consists predominantly of tricalcium phosphate ( -TCP) and -calcium pyrophosphate and has large-sized pores of 300–1000mm in diameter and small-sized pores of several tens micrometer in diameter. A new type of composite containing a large amount of -TCP was also prepared by heating the mixture of the mother glass powders with Ca(OH)2 at 800 C for 1 h. The amount of -TCP in the crystalline phase of the composites increased with increasing the Ca(OH)2 amount. The -TCP-containing glass-ceramic composites can be prepared by firing at a considerably lower temperature than a conventional -TCP ceramics. The amount of -TCP in the composites is controllable by variation of the Ca(OH)2 amount. The composites showed higher solubility in an acetic acid solution at 37 C with an initial pH value of 5.0 in comparison with PIGC. The solubility of one of the composites was comparable with that of pure -TCP. The composites are expected to be applicable for biodegradable scaffold for bone tissue engineering. [doi:10.2320/matertrans.48.313]