title: Influence of water on swelling and dissolution of cellulose in 1-ethyl-3-methylimidazolium acetate.
abstract: In this study the effect of residual coagulation medium (water) on cellulose dissolution in an ionic liquid is discussed. Solubility of dissolving grade pulp; HWP and SWP, and microcrystalline cellulose in binary solvents, mixtures of 1-ethyl-3-methyl-imidazolium acetate and water, was investigated by turbidity measurements, light microscopy, rheometry, and CP/MAS (13)C-NMR spectroscopy. The viscoelastic properties of the cellulose solutions imply that residual water affect the cellulose dissolution. However, it is not obvious that this always necessarily poses serious drawbacks for the solution properties or that the effects are as severe as previously believed. Turbidity measurements, viscosity data and crystallinity of the regenerated cellulose correlated well and an increased conversion to cellulose II was found at low water and cellulose contents with an apparent maximum of conversion at 2-5 wt% water. At high water content, above 10 wt%, dissolution and conversion was largely inhibited.
authors.affiliation: Organic Chemistry, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. Electronic address: carina.olsson@chalmers.se.
authors.forename: Carina
authors.initials: C
authors.lastname: Olsson
authors.forename: Alexander
authors.initials: A
authors.lastname: Idström
authors.forename: Lars
authors.initials: L
authors.lastname: Nordstierna
authors.forename: Gunnar
authors.initials: G
authors.lastname: Westman
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D004548:Elasticity; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009391:Nephelometry and Turbidimetry; D012995:Solubility; D012997:Solvents; D013696:Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry*
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; D012997:Solvents; D014867:Water; D002482:Cellulose; C109691:microcrystalline cellulose; C518739:1-ethyl-3-methylimidazolium
keywords: CP/MAS (13)C-NMR spectroscopy; Cellulose allomorph; EMIMAc; Ionic liquids; Regenerated cellulose; Rheology