Reaction behavior of cellulose in an ionic liquid, 1-ethyl-3-methylimidazolium chloride

We investigated the reaction behavior of cellulose in an ionic liquid, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), which can dissolve cellulose. The cellulose samples were treated with [C2mim][Cl] at 100, 120 and 140 °C. At the beginning of the treatment, the solubilized cellulose in [C2mim][Cl] is depolymerized into various low molecular weight compounds such as cellobiose, cellobiosan, glucose, levoglucosan and 5-hydroxymethylfurfural. As the treatment continued, some of the low molecular weight compounds reacted with the ionic liquid to form new polymers, which were black and contained nitrogen. [C2mim][Cl] is, therefore, not only a solvent for cellulose, but also a reagent for both depolymerization to produce various low molecular weight compounds, and subsequent polymerization of those compounds.