Effect of nitrile groups on conductivity and morphology of NBR/polyether-based electrolyte blends for antistatic materials

Abstract

Ion-conductive elastomer blends of commercial acrylonitrile-butadiene rubbers (NBR) rubber with polyether-based electrolyte were prepared as potential antistatic materials. Polyether-based electrolytes are usually very sensitive to humidity, because the electrolyte consists of hydrophilic polyether and metal salt. Here, we generated a nano-ordered phase-separated structure in the NBR blends so as to improve their stability against varying humidity environment. For better control of the conductivity in the semi-conductive region under differing conditions, we prepared NBR/polyether-based electrolyte blends with differing acrylonitrile (AN) content of NBR, and studied the effects of CN groups on the conductive properties and structures using a DC conductivity system, differential scanning calorimetry, Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). We found that the conductivity of the blends increased with increasing AN content of NBR, implying that CN groups having strong electron withdrawing properties interact with the dissociated K ions. The FT-IR and TEM measurements show that the concentration of the CN groups is a crucial factor in determining the morphology of each blends and the improvement in conductivity between the NBR and polyether phases.