Hydroxyapatite and CaO-TiO2-P2O5 system glass composites

To obtain mechanically strong biologically active ceramics at temperatures lower than the hydroxyapatite (HAp) sintering temperature, composites of glass and HAp with various weight relations of the components were synthesized. The CaO-TiO2-P2O5 system glasses modified with 2-10 mol.% of Na2O and HAp synthesized in the Biomaterils R and D Laboratory of the Riga Technical University were used for preparation of the composites. Increasing the content of Na2O in glass, crystallization temperature and synthesis temperature of glasses was decreased. Synthesized materials were investigated using the X-ray diffraction analysis and DTA. The main crystallization products obtained from the base glass are β-Ca2P2O7 and CaTi4(PO4)6. Along with increase of the content of Na2O in glasses crystallization of NaTi2(PO4)3 occurs. The main crystalline phases of composites are Ca5(PO4)3OH (HAp) and α- and β-Ca3(PO4)2. The tensile strength of composites is three times higher than the tensile strength of HAp ceramics and 3 times lower than the tensile strength of glass ceramics. (author)