Dissolution enthalpies of cellulose in ionic liquids

• Published in: Carbohydrate polymers Vol. 113; pp. 67 - 76
• Main Authors: Parviainen, Helena, Parviainen, Arno, Virtanen, Tommi, Kilpeläinen, Ilkka, Ahvenainen, Patrik, Serimaa, Ritva, Grönqvist, Stina, Maloney, Thaddeus, Maunu, Sirkka Liisa
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 26.11.2014; Elsevier
• Subjects: Applied sciences; Azabicyclo Compounds - chemistry; Calorimetry; Cellulose; Cellulose - chemistry; Cellulose and derivatives; Differential scanning calorimetry; Exact sciences and technology; Fibre dissolution; Imidazoles - chemistry; Ionic liquid; Ionic Liquids - chemistry; Microscopy; Natural polymers; Physicochemistry of polymers; Solubility; Thermodynamics; Differential scanning calorimetry; Fibre dissolution; Cellulose; Ionic liquid; Solvent effect; Imidazole derivatives; Structure effect; Iminium compounds; Angular nitrogen heterocycle; Experimental study; Dissolution; Mechanism; Mixed solvent; Bicyclic compound
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2014.07.001

•Dissolution of cellulose samples studied in different ionic liquids.•Dissolution of samples followed using optical microscope and DSC.•Exothermic transition was found prior to disappearance of outermost fibre layers.•Transition indicates interaction of solvent with cellulose. 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.