Dielectric Relaxation Behavior of Polymerized Ionic Liquid

Dynamic aspects of a polymerized ionic liquid, poly(1-ethyl-3-vinylimidazolium bis(trifluoromethanesulfonylimide)), were investigated using a broadband dielectric spectroscopy method in the frequency range of 10 mHz to 2 M Hz and temperatures ranging from -90 to +90 degrees C The polymerized ionic liquid shows three relaxation modes including the relaxation mode due to the effect of electrode polarization behavior We attribute the slow relaxation mode to the segmental motion of the polymer main chain and the last mode to the rotational motion of the polymer side chain. Relaxation times of these relaxation modes and the specific direct current conductivity showed an Arihenius-type temperature dependence at temperatures above and below the glass transition temperature of the polymer In order to explain the less fragile property of the polymerized ionic liquid, we propose that the ion transport mechanism is achieved by the formation and dissociation of ion-pairs formed between a positively charged 1-ethyl-3-vinylimidazolium monomer unit in a polymer chain and a negatively charged bis(trifluromethanesulfonylimide).