Dynamics of glassy clusters appearing by nonlinear dielectric effect studies

Preliminary results of time-resolved nonlinear dielectric effect (NDE) studies in the liquid, glassforming epoxy resin EPON 5 are presented. For all tested temperatures the NDE response of the sample parametrizes the stretched exponential function with exponent $\beta =0.38\mathrm{}\pm \mathrm{0.05.}$ The temperature evolution of relaxation times can be parametrized by means of the Vogel-Fulcher-Tammann function ${\tau }^{\mathrm{NDE}}={\tau }_0^{\mathrm{NDE}}\exp {(D}_{\mathrm{NDE}}{T}_0^{\mathrm{NDE}}/T-T_0^{\mathrm{NDE}}),$ with ${\tau }_0^{\mathrm{NDE}}\approx 0.3\mathrm{s},$ $D_E\approx 1.2,$ and $T_0^{\mathrm{NDE}}\approx 261\mathrm{K}.$ The latter value is, within the limit of the experimental error, equal to the glass temperature $T_g.$ The relaxation of “nonlinear” changes of the dielectric permittivity induced by a strong, steady electric field may be associated with the dynamic equilibrium of glassy clusters and the surrounding fluidlike region.