title: Dissolution enthalpies of cellulose in ionic liquids.
abstract: In this work, interactions between cellulose and ionic liquids were studied calorimetrically and by optical microscopy. Two novel ionic liquids (1,5-Diazabicyclo[4.3.0]non-5-enium propionate and N-methyl-1,5-diazabicyclo[4.3.0]non-5-enium dimethyl phosphate) and 1-ethyl-3-methylimidazolium acetate-water mixtures were used as solvents. Optical microscopy served in finding the extent of dissolution and identifying the dissolution pattern of the cellulose sample. Calorimetric studies identified a peak relating to dissolution of cellulose in solvent. The transition did, however, not indicate complete dissolution, but rather dissolution inside fibre or fibrils. This method was used to study differences between four cellulose samples with different pretreatment or origins.
authors.affiliation: Laboratory of Polymer Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Parviainen
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
authors.forename: Arno
authors.initials: A
authors.lastname: Parviainen
authors.affiliation: Laboratory of Polymer Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Virtanen
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Kilpeläinen
authors.affiliation: Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland.
authors.forename: Patrik
authors.initials: P
authors.lastname: Ahvenainen
authors.affiliation: Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland.
authors.forename: Ritva
authors.initials: R
authors.lastname: Serimaa
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Stina
authors.initials: S
authors.lastname: Grönqvist
authors.affiliation: Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, 00076 Aalto, Finland.
authors.forename: Thaddeus
authors.initials: T
authors.lastname: Maloney
authors.affiliation: Laboratory of Polymer Chemistry, Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland. Electronic address: sirkka.maunu@helsinki.fi.
authors.forename: Sirkka Liisa
authors.initials: SL
authors.lastname: Maunu
mesh_terms: D053961:Azabicyclo Compounds / Q000737:chemistry*; D002151:Calorimetry; D002482:Cellulose / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008853:Microscopy; D012995:Solubility; D013816:Thermodynamics
chemical_list: D053961:Azabicyclo Compounds; D007093:Imidazoles; D052578:Ionic Liquids; D002482:Cellulose; C518739:1-ethyl-3-methylimidazolium
keywords: Cellulose; Differential scanning calorimetry; Fibre dissolution; Ionic liquid