Dissolution of cellulose in ionic liquids and their mixed cosolvents: A review

Because of increasing environmental awareness and over-extrapolation of non-renewable materials, the application and processing of carbohydrate polymers (polysaccharides) have attracted immense courtesy as they are most abundant natural and biorenewable materials on the Earth. However, insolubility of the most of the polysaccharides in most of the common solvents including water limits their applications. Limited solubility of the polysaccharides is attributed because of the strong intermolecular interactions between polymeric chains that offer them high degree of crystallinity. More so, some organic solvents such as morpholine, N-methylmorpholine-N-oxide (NMMO), N-methylmorpholine (NMM), urea and thiourea in association with sodium hydroxide etc. were used to solubilise carbohydrate polymers with particular emphasis of cellulose. However, processing of the polysaccharides with these solvents is not only toxic to surrounding environment and living beings but also release several environmental malignant chemicals that can cause several side reactions and adversely affect their physiological properties. Present review paper features the collection of some major works that have been carried out in the area of cellulose dissolution in ionic liquids with and without co-solvents (DMSO, DMF, DMAc etc.).