Improvement of the stability and mechanical properties of resorbable phosphate glasses by the addition of TiO{sub}2

摘要

In this work, new formulations of phosphate glasses in the system P{sub}2O{sub}5-CaO-Na{sub}2O-TiO{sub}2 have been analysed. The rate of dissolution was evaluated by weight loss measurements in distilled water at 37°C and the mechanical properties were determined by microhardness and ultrasonic testing. Raman spectroscopy was used for studying the structure of the different glasses. The results showed that the addition of TiO{sub}2 lowered significantly the solubility of the glasses: the weight loss after 80 days, of the glass TiO{sub}2 free was 11%, and the addition of 8 mol% of TiO{sub}2 reduced the weight loss after the same period of time down to 1%. The Vickers hardness increased from 377,3 to 433,2, and the Young's modulus (E) varied respectively from 59,86 for the glass without titanium oxide up to 79,95 GPa for the glass containing 8mol% of TiO{sub}2. These results are discussed in terms of the structural changes induced by the introduction of titanium in the glass network. TiO{sub}2 reinforced calcium phosphate glasses are good candidates for biomedical applications due to their improved stability and enhanced mechanical properties.