Cellulose dissolution in diallylimidazolium methoxyacetate + N-methylpyrrolidinone mixture

Abstract

The utilization of cellulose in industrial applicat is of great significance to sustainable development of human society and reducing dependence on dwindling fossil resources. Nevertheless, this utilization of cellulose has actually been limited due to its insolubilization. Here, novel solvents consisting of diallylimidazolium methoxy acetate ([A₂im][CH₃OCH₂COO]) and N-methylpyrrolidinone (NMP) were developed. The solubility of cellulose in [A₂im][CH₃OCH₂COO]/NMP was determined, and the influence of [A₂im][CH₃OCH₂COO]/NMP molar ratio on cellulose dissolution was systematically investigated. Meanwhile, we also presented the affecting factors of the cellulose material fabrication including preparation approach, [A₂im][CH₃OCH₂COO] and cellulose solution concentration. Attractively, the [A₂im][CH₃OCH₂COO]/NMP solvents display much powerful dissolution capacity for cellulose even at 25 °C (25.4 g 100 g^-1). This is mainly ascribed to the combined factors: The hydrogen bond interactions of the H2, H4 and H6 in [A₂im]⁺ and carboxyl O atom in [CH₃OCH₂COO]^- with the hydroxyl H atom and O atom in cellulose; the dissociation of NMP towards [A₂im][CH₃OCH₂COO]; the stabilization of NMP towards the dissolved cellulose chains. In addition, the thermostability and chemical structure of the regenerated cellulose from the solvents was also estimated.