A generalized domain approach for describing the stress relaxation in a phase separated borosilicate glass

In this work we propose a generalized domain approach for modeling the stress relaxation behavior of phase õseparated borosilicate glasses. The generalization of the domain approach is done by taking two fundamental steps. First, we assume the boron groups to be the soft boundaries in the borosilicate glasses. Second, we introduce the time-dependent power law into the Kohlrausch function. Using the generalized domain approach, we explained why the value of the stretched exponent of the stress relaxation in borosilicate glasses anomalously deviates from the converged exponent value of 3/5. In addition, we introduce a pre-time, i.e., the time for glass to reach the structural equilibrium, into the generalized domain approach in order to compensate the variation of viscosity caused by phase separation. It is found that the pre-time is closely correlated with the time for borosilicate glasses to reach structural equilibrium before stress relaxation experiment.