Cellulose is one of the most abundant biological and renewable materials in the world and is widely used in various industries. However, further expansion of the use of cellulose or cellulosic materials has been hampered by its poor solubility in common organic solvents.) But a relatively new family of solvents for cellulose has emerged. They are ionic liquids (ILs), organic salts with a low melting temperature, which makes them suitable as solvents. Moreover, ILs are non-volatile, non-toxic, non-flammable and thermally and chemically stable. Cellulose dissolved in ILs can be regenerated with water, ethanol, or acetone. In this study, the hardwood and softwood dissolving pulps were pretreated with two ILs – [C4mim+]CH3COO– and [C4mim+]Cl–. The impact of the pretreatment on the molecular weight distribution of the cellulose, its thermal stability, morphology and crystallinity was evaluated using analytical techniques such as size exclusion chromatography (SEC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and solid state cross-polarization/magic angle spinning 13C (CP/MAS) nuclear magnetic resonance (NMR).
cellulose; dissolving pulp; dissolution; regeneration; ionic liquids (ILs); molecular weight distribution; thermal stability; morphology; crystallinity