The relationship between properties and glass structure is, perhaps, more clearly evident in borate and in borosilicates than it is in any other family of glasses. Nuclear magnetic resonance measurements have shown that, at room temperature, the manner in which oxygen bonds to boron depends on the ratio of alkali to boron. A satistical mechanical model indicated that the bonding is influenced by temperature and it was used to calculate the relative numbers of various structual units for the glass as a function of compostion and temperature. The reuslts exhibit a reasonably good correlation with the measured strain points and softening points. A model for the halogen solubility as a function of temperature and of matrix compositon was also developed.
