Preparation and characterization of calcium phosphate glass fiber

Abstract

To produce and investigate the behavior calcium phosphate glass fibers. Calcium phosphate glasses were prepared by reacting calcium carbonate with orthophosphoric acid and melted to glasses with the compositions having the CaO:P[subscript 2]O[subscript 5] ratios of 50:50, 51.1:48.9, and 51.9:48.1 mol%. The glass samples were classified into 4 types: CPG, CPG1, CPG2, and CPG3. CPG was a glass which contained CaO:P[subscript 2]O[subscript 5] ratio of 50:50 mol% and melted in a Pt crucible, while CPG1, CPG2, and CPG3 were those which contained CaO:P[subscript 2]O[subscript 5] ratios of 50:50, 51.1:48.9, and 51.9:48.1 mol% and melted in a clay crucible, respectively. The study on nucleation and crystallization by Differential Thermal Analysis (DTA) found that each CPG, CPG1, CPG2, and CPG3 had the maximum nucleation temperature at 487 ํC, 569 ํC, 559 ํC, and 579 ํC, respectively. The activation energy of crystallization of each CPG, CPG1, CPG2, and CPG3 was 117.9, 363.3 236.8, and 244.3 kJ/mol, respectively. Finally, the mechanism of crystallization was determined. The CPG and CPG3 were as a bulk crystallization, CPG1 was as a surface crystallization, and CPG2 was as a surface crystallization along with a bulk crystallization. The formation of glass fibers had been attempted. CPG1 was the only composition able to be drawn as short fiber by direct melt method at 1100 ํC.