title: Deconstruction of Nordic hardwood in switchable ionic liquids and acylation of the dissolved cellulose.
abstract: Nordic hardwood (Betula pendula) was fractionated in a batch autoclave equipped with a custom-made SpinChem(®) rotating bed reactor, at 120 °C using CO2 and CS2-based switchable ionic liquids systems. Analyses of the non-dissolved wood after treatment showed that 64 wt% of hemicelluloses and 70 wt% of lignin were removed from the native wood. Long processing periods or successive short-time treatments using fresh SILs further decreased the amount of hemicelluloses and lignin in the non-dissolved fraction to 12 and 15 wt%, respectively. The cellulose-rich fraction was partially dissolved in an organic superbase and an ionic liquid system for further derivatization. Homogeneous acylation of the dissolved cellulose in the presence or absence of catalyst resulted in cellulose acetates with variable degree of substitution (DS), depending on the treatment conditions. By varying the reaction conditions, the cellulose acetate with the desired DS could be obtained under mild conditions.
authors.affiliation: Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University, SE-901 87 Umeå, Sweden; Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku FI-20500, Finland. Electronic address: valerie.eta@abo.fi.
authors.forename: Valerie
authors.initials: V
authors.lastname: Eta
authors.affiliation: Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University, SE-901 87 Umeå, Sweden; Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku FI-20500, Finland.
authors.forename: Jyri-Pekka
authors.initials: JP
authors.lastname: Mikkola
mesh_terms: D000215:Acylation; D029662:Betula / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry*; D006868:Hydrolysis; D052578:Ionic Liquids / Q000737:chemistry*; D014934:Wood / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D002482:Cellulose
keywords: Birch; Cellulose; Cellulose acetate; Degree of substitution; Switchable ionic liquids (SILs); Wood fractionation