Facile cellulose dissolution without heating in [C₄mim][CH ₃COO]/DMF solvent

Novel cellulose solvents, [C4mim][CH3COO]/DMF, were designed by adding an aprotic polar solvent N,N-dimethylformamide (DMF) in 1-butyl-3-methylimidazolium acetate ([C4mim][CH3COO]). The solubilities of cellulose in [C4mim][CH3COO]/DMF solvents were determined at 25°C. The effects of molar ratio of DMF to [C4mim][CH3COO] on cellulose solubility and the possible dissolution mechanism of cellulose in [C4mim][CH3COO]/DMF solvent have been studied. Moreover, the regenerated cellulose from [C4mim][CH3COO]/DMF solvent were characterized by scanning electron micrograph (SEM) Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), and the degree of polymerization (DP) of regenerated cellulose was determined. The findings reveal that the facile dissolution of cellulose in such solvents is mainly attributed to the increased "free" [CH3COO](-) anions and [C4mim](+) cations which result from the dissociation of [C4mim][CH3COO] by DMF. Moreover, the macromolecular chain of the cellulose is hardly broken during the dissolution and precipitation processes.