Mild condition dissolution of high molecular weight cotton cellulose in 1-butyl-3-methylimidazolium acetate/N,N-dimethylacetamide solvent system

To investigate the effective dissolution of high molecular weight (MW) cellulose macromolecules at ambient conditions, cellulose (DP > 4,000) derived from cotton fiber waste was dissolved in 1-butyl-3-methylimidazolium acetate (BMIMAc)/N,N-dimethylacetamide (DMAc) solvent in this study. High MW cotton cellulose achieves a solubility between 3% and 5% cellulose concentrations using BMIMAc/DMAc solvent at ambient conditions. Rheological studies showed that all cellulose/solvent solutions displayed a shear thinning behavior. Results from the physical characterization revealed that well-dissolved cotton cellulose exhibited highly porous structure and the crystalline structure of cotton cellulose was highly disrupted during dissolution and regeneration processes. This study is the first to report on the ability of BMIMAc/DMAc solvent system to dissolve high MW cellulose under ambient conditions, which represents an energy-saving and environmentally friendly approach. As cellulose used in this study was derived from low quality waste cotton fibers, the potential utilization of such cotton cellulose may create a competitive market for low quality cotton and target advanced applications of cellulose-based products for green materials and energy. (C) 2017 Wiley Periodicals, Inc.