A new biodegradable polymeric material (Cell-Im) consisting of microcrystalline cellulose (Cell) and imidazole (Im) dopant was successfully synthesized. The thermal properties and proton conductivity of Cell-Im were determined and compared with that of pure microcrystalline cellulose. It was found that the Cell-Im exhibits close to four orders of magnitude higher conductivity than a pure cellulose sample, up to approximately 2 x 10(-4) S/m at 160 degrees C under anhydrous conditions. Thermal stability of Cell-Im was confirmed above water boiling point in a temperature range from 110 to about 150 degrees C. The Cell-Im is inexpensive to obtain, non-hazardous and environmentally friendly and can have potential for possible application as a solid electrolyte in electrochemical devices. (C) 2015 Published by Elsevier Ltd.