REACTION OF β-TRICALCIUM PHOSPHATE WITH NAOH SOLUTIONS RANGING FROM 0.8 TO 50 MASS%
2004 年 17 巻 p. 165-169
詳細
2004 年 17 巻 p. 165-169
Details of the reaction of β-tricalcium phosphate (β-TCP) with NaOH solution at 90°C were clarified in a NaOH concentration wider range than that previously reported. At a 0.8 mass% NaOH solution, no reaction occurred even after 6 d. At 2-23 mass% the simple reaction β-TCP→hydroxyapatite (HAp) occurred and its completion reaction time reduced from over 24h at 2 mass% to within 1.0h at 23 mass%. At 24-33 mass% the consecutive reaction β-TCP→Ca(OH)2→HAp occurred. where the first step was comparatively fast and the second was slow. The second step proceed completely at 24-25 mass%, whereas at 30-33 mass% reached an equilibrium mixture of 85%HAp and 15%Ca(OH)2. At 34-50 mass% the simple reaction β-TCP→Ca(OH)2 was completed within 0.5h, and no subsequent change occurred. The solubility singular points in the system β-TCP-Ca(OH)2-HAp were estimated to be 23 mass% (7.1 mol/dm3) for the β-TCP-Ca(OH)2 system, and 32 mass% (10.8 mol/dm3) for the Ca(OH)2-HAp system.
