Comparison of rheological behavior and spinning performance of cellulose dopes using two kinds of imidazole-based ionic liquids as solvents

摘要

In this paper, two kinds of imidazole-based ionic liquids, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) and 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac), were used as the solvents of cellulose. The dissolving characteristics of cellulose in these two ionic liquids were investigated with polarizing microscope. The rheological behavior and spinning performance of these two cellulose solutions from [EMIM]Ac and [BMIM]Cl were investigated. The results showed that cellulose had lower dissolution temperature and faster velocity in [EMIM]Ac, compared with [BMIM]Cl. Both cellulose solutions belonged to typical shear thinning fluids. At the same condition, the apparent viscosity of the cellulose/[EMIM]Ac solution was lower than that of cellulose/[BMIM]Cl solution, indicating that the cellulose/[EMIM]Ac solution could be spun at a lower temperature. GPC results showed that during the dissolution and spinning process, the degradation of cellulose in [BMIM]C1 was greater than one in [EMIM]Ac. Moreover, it was found that the orientation, crystallinity, breaking tenacity and initial modulus of the cellulose fibre regenerated from [BMIM]Cl were higher than those from [EMIM]Ac.