The electrochemical impedance spectroscopy (EIS) was employed to estimate resistivity of a novel epoxy coating with various molar fractions of glycerol diglycidyle ether (GDE) and 3,3-dimethylglutaric anhydride (DGA) over frequency range of 100 to 100 kHz. The effects of curing time, initiator concentration, temperature, and amount of nano-Al2O3 on dielectric response of the nanocomposite were reported. Dynamic mechanical thermal analysis (DMTA) measurements revealed that two sub-Tg relaxation peaks could be recognized as well. These relaxation processes were attributed to the thermally activated motion of specific groups or the network segments. The relaxation peaks have been detected from the EIS measurements in the form of Bode diagram for all the studied samples. This research highlights that the presence of nanoalumina does not change the dielectric response and molecular dynamic of the nanocomposite considerably, while the influences of the other investigated parameters are significant.
