Density, surface tension and viscosity of the molten Pbo-B2O3-SiO2 system

Abstract

The density, surface tension and viscosity of the molten PbO-B2O3-SiO2 system were measured for high packaging industry. The compositional dependence of the properties has been investigated. The results were shown as follows. The density of melt increase linearly with increasing PbO content. The molar volume was estimated from the density data and its deviation from additivity was calculated. It was considered that Pb2+ ions may act as a network former for PbO content more than 40-50 mol%. The surface tension decreased with decreasing the ratio SiO2/XB2O2, and its value increased at 30 60 mol%, respectively. The viscosity of melt decreased linearly with increasing the PbO content. To predict the viscosity, an empirical equation between viscosity and molar equivalent weight was obtained, from which the effect of viscosity; B2O2=SiO2 × 0.5 was presumed.