title: Simultaneous bench scale production of dissolving grade pulp and valuable hemicelluloses from softwood kraft pulp by ionic liquid extraction.
abstract: Ionic liquid extraction of wood pulp has been highlighted as a highly potential new process for dissolving pulp production. Coproduction with a polymeric hemicellulose fraction was demonstrated in bench scale from softwood kraft pulp using extraction with the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc) and water. In total, the recovered pulp and hemicellulose fraction together yielded 95.5 wt.% of the pulp input. The extracted pulp had a remarkably high purity with an R18-value of 97.8%. The hemicellulose fraction consisted of galactoglucomannan, arabinoxylan and some cellulose and was precipitated from the ionic liquid-water mixture. After hydroxypropylation of the hemicellulose fraction, films were prepared and barrier and strength properties were compared to films from other polysaccharides. Reduced oxygen and water vapor permeation and good strength properties were demonstrated when compared to corresponding films from hydroxypropylated xylan from cold caustic extraction. The films have potential for applications in food packaging and edible films.
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland. Electronic address: christiane.laine@vtt.fi.
authors.forename: Christiane
authors.initials: C
authors.lastname: Laine
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland. Electronic address: sari.asikainen@vtt.fi.
authors.forename: Sari
authors.initials: S
authors.lastname: Asikainen
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland. Electronic address: riku.talja@metsagroup.com.
authors.forename: Riku
authors.initials: R
authors.lastname: Talja
authors.affiliation: Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland. Electronic address: agnes.stepan@aalto.fi.
authors.forename: Agnes
authors.initials: A
authors.lastname: Stépán
authors.affiliation: Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland. Electronic address: herbert.sixta@aalto.fi.
authors.forename: Herbert
authors.initials: H
authors.lastname: Sixta
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT, Finland. Electronic address: ali.harlin@vtt.fi.
authors.forename: Ali
authors.initials: A
authors.lastname: Harlin
keywords: Barrier film; Dissolving pulp; Hemicellulose; Ionic liquid; Modification; Strength properties; Wood pulp