A study on thermal properties of β-Ca(PO3)2 whiskers and on devitrification mechanism of calcium phosphate glass system

beta-Ca(PO3)(2) whiskers were successfully extracted from crystallized calcium phosphate glasses by leaching with distilled water or aqueous solution of 0.1-0.5 N NaOH. beta-Ca(PO3)(2)whiskers of aspect ratios (16-400) were obtained from the crystallized glasses with Ca/P molar ratio smaller than 0.4. It is expected that the beta-Ca(PO3), whiskers are available for new applications to biomedical fields. In this study, the morphology and the melting point of beta-Ca(PO3)(2) whiskers that obtain from the crystallized glasses with different particle size will be investigated. beta-Ca(PO3)(2) whiskers having aspect ratios of(16-400) with diameter of 3-30 mu m was found from a crystallized glass with Ca/P molar ratio of 0.25, but the morphology of beta-Ca(PO3)(2) whiskers of crystallized glass before leaching are not clear because of the existence of glass phase, so the extraction step is needed for preparation of the beta-Ca(PO3)(2) whiskers. The curves of TG and DTA for the resultant powder before extraction step gave a high mass loss percentage (approximation 14%) and melt completely at about 900 degrees C with a broad endothermic peak in DTA curve. But the resultant whiskers that after extraction step gave only 1% mass loss in TG curve and melt completely at 980 degrees C with a sharp endothermic peak. (C) 1999 Published by Elsevier Science B.V. All rights reserved.