Effect of the anion of ionic liquid for dissolution of cellulose

Cellulose, the most abundant polymer from nature, is regarded as an important source for bio-ethanol and bio-butanol. Cellulose dissolution and regeneration were conducted by using of 1-butyl-3-methylimidazolium-based ionic liquids with different anion. The degree of dissolution was closely related with coordinating ability of the anion in ionic liquid, that is, less coordinating or non-coordinating anions such as BF4-, PF6- and TFSI- showed poor solubility for cellulose, while coordinating anions, e.g., halide, carboxylate, and bicarbonate, dissolve cellulose up to 20 wt % depending on the experimental condition. After dissolution, the cellulose was regenerated and then analyzed. Depending on the heating method and ionic liquid used, regenerated celluloses showed different morphology and chemical properties. This is an abstract of a paper presented at the 2008 AIChE Spring National Meeting (New Orleans, LA 4/6-10/2008).