Study of co-solvent effect on the dissolution of cellulose in ionic liquid and the properties of regenerated cellulose fibres

We have developed a novel and economy process to dissolve high concentration of microcrystalline cellulose in ionic liquid using dimethyl sulfoxide (DMSO) as co-solvent, and to produce strong regenerated cellulose fibres from the solution. Highly aligned cellulose fibre has been dry-jet wet spun from optically anisotropic microcrystalline cellulose/1-ethyl-3-methylimidazolium diethyl phosphate (EMImDEP)/dimethyl sulfoxide (DMSO) solution. The 20.8 wt% cellulose solution shows strongly optically anisotropic patterns, with a clearing temperature of ~100°C. The cellulose fibre possesses an average diameter of 28.6 μm, moderately high Young’s modulus of 27.8 GPa, and tensile strength of 387.7 MPa. This process presents a new route to convert a high concentration of microcrystalline cellulose into strong fibres, while reduces the processing time and cost significantly, which can potentially be used as high-performance fibres for composite materials as well as precursors for carbon fibres.