The reaction of cellulose with CO2 in the presence of series of organic superbases led to a novel solution strategy for CO2 derivatives of cellulose, which is a special solvent system for cellulose dissolution processing and derivatization. The properties of the cellulose solution are excellent for the production of certain regenerated materials through dissolution processing. Herein, cellulose dissolving properties in CO2 / 1.8-diazabicyclo[5.4.0] undec-7-en / dimethyl sulfoxide (CO2 / DBU / DMSO) as a solvent system were initially systematically investigated and it was found that the apparent viscosities of cellulose solutions strongly depend on the type, concentration and temperature of the cellulose. The overlap concentration (c *) was determined to be 2 and 0.6% by weight for MCC and wood pulp solutions, respectively. The Cox-Merz rule applied to cellulose solutions in the CO2 / DBU / DMSO solvent system. In addition, using the reversible chemistry of CO2 in this solvent system, a reversible CO2-controlled sol-gel transition of the newly achieved cellulose solution into CO2 / DBU / DMSO was identified through the dynamic rheology of the measurement of the temperature dependency of the storage module (G ‘) and Loss modulus (G ”). In addition, the interesting CO2-controlled sol-gel transition was developed via an integrated thermally induced CO2 release and anti-solvent extraction for the production of regenerated cellulose gel materials and then cellulose films with a tensile strength of 44.3 MPa. Interestingly, it turned out that the regenerated cellulose has a crystalline structure of Cellulose IVI by this approach.

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