Superior Solubility of Polysaccharides in Low Viscosity, Polar, and Halogen-Free 1,3-Dialkylimidazolium Formates

Abstract

We successfully prepared low viscosity, polar, and halogen-free ionic liquids as potential solvents for a wide range of polysaccharides. A series of 1,3-dialkylimidazolium formates were produced as liquids having strong hydrogen bond acceptability. These formates had significantly lower viscosity than previously reported polar ionic liquids, in particular 1-allyl-3-methylimidazolium formate (viscosity 66cP at 25 °C) and 1-allyl-3-ethylimidazolium formate (67cP at 25 °C). Because of their strong hydrogen bond ability, various polysaccharides including amylose and (scarcely soluble) cellulose were dissolved in high concentrations under mild condition.