Synthesis and Characterization of Nitrile-functionalized Azepanium Ionic Liquids for the Dissolution of Cellulose

The solubility of cellulose in common solvents are very low. In order to overcome this problem, synthesis of nitrile-functionalized azepanium ionic liquids such as 1-butyl-1-(2-cyano-ethyl)-azepanium bromide, 1-butyl-1-(2-cyano-ethyl)-azepanium trifluoromethane sulfonate and 1-butyl-1-(2-cyano-ethyl)-azepanium trifluoro acetate were performed to test their cellulose solubilizing potential. 1H NMR, 13C NMR and CHN elemental analysis were used to characterize the synthesized ionic liquids. Thermo gravimetric analysis (TGA) and Differential Scanning Calorimetry(DSC) were used to determine the thermal properties of the ionic liquids. The ionic liquids were used for the dissolution of cellulose. Azepanium based nitrile-functionalized ionic liquids were able to dissolve up to 2 wt % of cellulose at 120 ̊C in 48 hours. Thermal decomposition temperature and surface morphology of the cellulose was measured before and after the dissolution studies.The FTIR results showed that azepanium based ionic liquids are dissolving cellulose without any functionalization.