Low waste process of rapid cellulose transesterification using ionic liquid/DMSO mixed solvent: Towards more...

The recent progress in the manufacturing of new functional cellulose-derived materials shows that the renewable side of these materials does not ensure sustainable development. In contrast, reaction/process design and waste minimization play a key role here. Herein, reactive extrusion was used as a fast method for cellulose transesterification with vinyl laurate in 1-ethyl-3-methylimidazolium acetate (EmimOAc)/DMSO system. It was demonstrated that cellulose laurate can be synthesized with high reaction efficiency (91 %). The low amount of solvent during the process provides high cellulose concentration (20 wt%) mild chemical modification within minutes and without any depolymerization. Temperature has a significant influence on the reaction kinetics. To examine the sustainability of the process E-factor was employed. Processing properties of obtained cellulose laurates were investigated. Samples with DS of 2.5 and higher can be easily extruded showing low melt viscosity. EmimOAc was recovered and reused for subsequent cellulose transesterification exhibiting high catalytic activity.