Phase diagram, solubility limit and hydrodynamic properties of cellulose in binary solvents with ionic liquid

Carbohydr Polym. 2014 May 25:105:237-43. doi: 10.1016/j.carbpol.2014.01.085. Epub 2014 Feb 2.

Abstract

Cellulose solubility phase diagrams in two binary solvents based on 1-ethyl-3-methylimidazolium acetate (EmimAc) mixed with water and with dimethylsulfoxide (DMSO) were built. The minimal amount of EmimAc molecules needed to dissolve cellulose is 2.5-3moles per anhydroglucose unit. This proportion allows calculation of the maximal cellulose concentration soluble in EmimAc-DMSO at any composition; in EmimAc it is around 25-27wt%. Water forms hydrogen bonds with EmimAc and thus competes with cellulose for ionic liquid; the solubility of cellulose in EmimAc-water is much lower than that in EmimAc-DMSO. Hydrodynamic properties of cellulose in two solvent systems were compared. In EmimAc-DMSO cellulose intrinsic viscosity practically does not depend on DMSO content as predicted by the phase diagram. The intrinsic viscosity in EmimAc-water first increases with water content due to cellulose self-aggregation and then abruptly decreases due to coagulation.

Keywords: Cellulose; DMSO; Intrinsic viscosity; Ionic liquid; Phase diagram; Solubility; Water.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cellulose / chemistry*
  • Dimethyl Sulfoxide / chemistry*
  • Hydrodynamics
  • Imidazoles / chemistry*
  • Ionic Liquids / chemistry*
  • Phase Transition
  • Solubility
  • Solvents / chemistry
  • Viscosity
  • Water / chemistry*

Substances

  • Imidazoles
  • Ionic Liquids
  • Solvents
  • Water
  • Cellulose
  • 1-ethyl-3-methylimidazolium
  • Dimethyl Sulfoxide