Effects of a Distribution of Volume Relaxation Times in the Annealing of BSC Glass.

Abstract

The influence of a distribution of relaxation times is studied in annealing experiments. A two-relaxation time model is proposed, which permits the calculation of the distribution of relaxation times from the crossover data of Spinner and Napolitano as well as that of Ritland. This model also characterizes the structure of any glass in terms of two parameters. Thus, quenched equilibrium as well as nonequilibrium glass were compared with rate cooled glasses with respect to their behavior upon further annealing as well as their conductivity at low temperatures with excellent agreement. Borosilicate crown glass was found to have a narrow distribution of relaxation times which is particular to associated liquid monomers rather than polymers. The results can be explained in terms of a topological model for the distribution of relaxation times. The temperature dependence of the viscosity is due to a true activation energy rather than a free volume effect.