Fabrication of cellulose article from dope comprising ionic liquid and aprotic co-solvent

摘要

Cellulose is at least partially dissolved in a dope at â ! 100(70)°C. Cellulose shaped articles are cast from the cellulose solution. Preferably the dope comprises 20-50(25-35) wt% ionic liquid, 1-10(3-8) wt% nitrogen containing base and polar aprotic cosolvent, especially dimethyl sulphoxide (DMSO), tetrahydrofuran (THF), dimethylacetamide (DMAc), dimethylformaide (DMF), formamide, N-methylmorpholineoxide (NMMO), pyridine, acetone, dioxane, N-methylpyrrolidone, piperyline sulphone or hexamethylphophoramide. Preferred ionic liquids are 1-ethyl-3-methyl imidazolium (EMIM) chloride (Cl) or acetate, 1-butyl-3-methyl imidazolium [c4min]+ Cl, 1-allyl-3-Me imidazolium Cl, zinc chloride / choline chloride, 3-methyl-N-butyl-pyridinium Cl, benzyldimethyl (tetradecyl) ammonium Cl or 1-methylimidazole hydrochloride. The solution contained 1-20(8-12) wt% cellulose having degree of polymerisation â ¤ 500 and viscosity = 5,000-12,000 cp. The solution is wet spun into a casting solution comprising a non-solvent (water). The fibres produced are used in ropes, yarns, cloths and cigarette filters.