Preparation of high-temperature stabilized beta-tricalcium phosphate by heating deficient hydroxyapatite with Na4P2O7 x 10H2O addition.
In this paper, the high-temperature stabilized beta-tricalcium phosphate (betaTCP, beta-Ca3(PO4)2) were prepared by heating the deficient HAP (d-HAP, Ca10-x(HPO4)x(PO4)6-x(OH)2-x) with tetra-sodium diphosphate decahydrate (NP, Na4P2O7 x 10H2O) addition. The betaTCP, d-HAP and d-HAP doped with 2.5, 5, 7.5 and 10 wt % NP were heated to different temperatures and were investigated by X-ray diffraction analysis (XRD) and Fourier-transformed infrared spectroscopy (FTIR). The results demonstrated that the HPO4(2-) of d-HAP condensed into P2O7(4-) occurred before 650 degrees C. The P2O7(4-) ions could be traced in the FTIR spectrum when the d-HAP was heated up to 750 degrees C. The reaction of P2O7(4-) with OH- did not occur instantly but over a wide range of temperatures. The d-HAP doped with NP would decrease the decomposition temperature of d-HAP. NP doped into d-HAP not only induced the d-HAP decomposition at lower temperature but also stabilized the betaTCP crystal structure at higher-temperature. It could also increase the conversion temperature of betaTCP to alphaTCP from 1180 degrees C up to 1300 degrees C. We could successfully prepare high-temperature (up to 1300 C) stabilized ffTCP by heating NP doped d-HAP.
Lin
F H
FH
Center for Biomedical Engineering, College of Medicine, National Taiwan University, Taipei, ROC.
Liao
C J
CJ
Chen
K S
KS
Sun
J S
JS
D002130:Calcium Phosphates / Q000138:chemical synthesis*; D011756:Diphosphates / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D006358:Hot Temperature; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
D002130:Calcium Phosphates; D011756:Diphosphates; C485817:beta-tricalcium phosphate; D017886:Durapatite; C018392:tricalcium phosphate; C003319:sodium pyrophosphate