Abstract
A new water-soluble ionocellulose material bearing imidazolium tosylate groups was synthesized in a two-step sequence from cellulose, and the electrical conduction properties of this bio sourced polyelectrolyte were investigated. First, tosylcellulose was prepared from neat cellulose and tosyl chloride in the ionic liquid 1-Butyl-3-methylimidazolium chloride [BMIM]Cl. Then, the ionocellulose containing imidazolium tosylate grafts was synthesized by reacting tosylcellulose and 1-methylimidazole. Both tosylcellulose and ionocellulose were characterized by different analytical techniques including elemental analysis, 13C NMR and FT-IR spectroscopy as well as thermogravimetric analysis. We then compared the dielectric relaxation of neat cellulose with ionocellulose. For both samples, two secondary relaxations were identified at low temperature. These two relaxations became faster in ionocellulose containing imidazolium tosylate grafts. At higher temperatures (T > room temperature), the conductivity is markedly dominated by ionic motions. This work opens new perspectives for preparing a new category of ionocellulose derivatives which are expected to find applications in energy storage technologies and for the elaboration as novel high-performance film dielectric capacitors.