Influence of addition of Al2O3 on physical, structural, acoustical and in-vitro bioactive properties of phosphate glasses

Four different formulations of phosphate glasses in the system P2O5-CaO-Na2O-Al2O3 were developed. The elastic moduli have been obtained using the known method at room temperature. Their physicochemical and structural evolution was analyzed during in-vitro degradation in SBF (simulating body fluid) at 37 degrees C after 30 days. The results showed that the weight loss of the glass is greatly reduced with the incorporation of only 3 mol% of Al2O3 in P2O5-CaO-Na2O glass composition. Fourier transform infrared (FTIR) spectroscopy performed on glasses before and after dipping in SBF showed calcium phosphate glasses in the system P2O5-CaO-Na2O reinforced with Al2O3 offer an interesting option for slowly resorbable materials as compared to other calcium phosphate glasses with high degradation velocity. The chemical formulation of these glasses allows the synthesis of materials with a controlled solubility. However, the substitution of Al2O3 <= 5 mol% negatively affects the bioactivity of the P2O5-CaO-Na2O glasses. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim