Dielectric Relaxation of Curing DGEBA/mPDA System at 2.45 GHz

The dielectric behavior of a curing system of diglycidyl ether of bisphenol A and m-phenylenediamine has been studied over the temperature range of 20-100 degrees C under 2.45GHz microwave radiation. The dielectric constant and the dielectric loss factor of the system increase as temperature increases while they decrease as the curing reaction progresses. The epoxy resins at different extents of cure exhibit the gamma relaxation, which can be described by the Arrhenius rate law. The relaxation is attributed to the motions of the dipolar groups associated with the crosslinking system. The Davidson-Cole model is used to represent the temperature dependency of the dielectric properties.