Network connectivity and dissolution properties of sodium calcium phosphate glasses

Abstract Glasses of xCaO∙(80-x)P 2 O 5 ·20Na 2 O system (0 ≤ x ≤ 30% mol %) with constant Na 2 O content were studied in order to evidence both structural and dissolution properties determined by CaO addition. Transparent vitreous samples were obtained in the investigated composition range. Thermal analysis evidenced the increase of both crystallisation and melting temperatures with CaO content. The relative mass loss of samples in simulated body fluid progressively increased with the extent of P 2 O 5 substitution by CaO. The dissolution properties could be explained in relation with the structural changes concerning the PO 4 units connectivity as pointed out by DTA and FTIR analysis.