LAUSR

Abstract A low-melting group of glass was prepared to examine the function of MoO3 on the synthesis and properties of sodium calcium fluorophosphate glasses. The glass specimens were synthesized based on Na2O CaO MoO3 P2O5 CaF2 system by the melting quenching method. The effect of adding MoO3 at the expense of CaO on the structure, mechanical, thermal, and chemical properties of the glasses was studied. The FTIR results proved that there is no evidence of a formation of the Mo-O linkages in the infrared spectral range. The density and molar volume of the prepared glasses were studied. Glass density enhanced whereas molar volume declined with MoO3 content. The Vickers hardness of the glass specimens was found to be decreasing with the MoO3/CaO replacement percent due to the weakening of the glass structure. The dilatometric thermal measurements showed the decrease of both transition temperature Tg and softening temperature Ts with MoO3 content. However, the thermal expansion coefficients values were increased from 101 × 10−7 to 110 × 10−7/°C1. The chemical solubility of the prepared glasses was examined by immersing in distilled water for 21 days. The results showed that the MoO3/CaO replacement helped to improve the glass solubility significantly. So, depending on the properties examined the glasses have the potential to be used as promising low-melting sealing materials.