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 & sdot;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.