Effective dissolution of cellulose in a DESs mixed solvent system

The dissolution of cellulose is an essential prerequisite for the development and utilization of cellulose. Here, a mixed solvent system containing deep eutectic solvents (DESs) and non-protonic organic solvents was prepared for the dissolution of three kinds of cellulose. This solvent system exhibited excellent ability for the dissolution of cellulose. The prepared mixed solvent system, comprising DESs synthesized from 1,1,3,3-tetramethylguanidine and acetic acid in combination with dimethyl sulfoxide and N , N -dimethylacetamide, could dissolve up to 29 wt% of microcrystalline cellulose, 24 wt% of bleached eucalyptus kraft pulp and 16 wt% of purified cotton with high polymerization degree at 80 °C. “Conjoining ion pairs” may be the main role in destroying the hydrogen bonds and promoting the dissolution of cellulose. The polymerization degree of the three regenerated celluloses only slightly decreased, and their infrared spectra did not show significant changes. This solvent system is inexpensive, easy to prepare, and recyclable.