Systematic assessment of the compositional dominance over physico-chemical properties in the SiO2-Al2O3-B2O3 based glassy networks

Abstract

Series of seven aluminoborosilicate glasses was studied by means of thermo-analytical and spectroscopic methods to identify the influence of the individual network-forming oxides (SiO₂, Al₂O₃ and B₂O₃) on the particular classes of measured properties. The compositional correlation of the observed trends was enumerated by means of multilinear regression analysis. The base physico-chemical properties, such as density, refractive index and molar refractivity, were found to be a linearly additive combination of the roughly equally weighted contributions of the three network-forming oxides. The thermo-mechanical properties, i.e., the glass transition temperature (determined from volume, enthalpy and viscosity measurements) as well as coefficients of thermal expansion, were dominantly determined by the Al₂O₃ content. On the other hand, the internal properties of the viscous flow measured in the 10⁷ – 10¹¹ Pa·s range, i.e., the activation energy of viscous flow and kinetic fragility (defined under the Angell's concept) were driven by the B₂O₃ content.