Effects of Pressure and Temperature on the Dissolution of Cellulose in Ionic Liquids

Abstract

Cellulose –Earth’s most abundant biopolymer–represent an enormous carbon-neutral renewable resource of biomaterials and bioenergy. The dissolution of cellulose with environmentally friendly and efficient solvents/methods is an important and challenging for further chemical processing. In recent years, room temperature ionic liquids (ILs)- a attractive “green” and “designer” solvent-have emerged as a potentially attractive “green” solvent for dissolution of cellulose for further processing. In general, dissolution of cellulose in ILs via conventional heating system requires high temperature and long pretreatment time. This study reports the effect of pressure on the dissolution of cellulose in IL [C2mim][OAc] (1-ethyl-3-methylimidazolium acetate). The effects of temperature and pressure on cellulose dissolution time were investigated using high Pressure Solubility Measurement System (HPSMS). It was found that as the pressure and temperature increased, the dissolution time decreased significantly. For comparison, the original microcrystalline cellulose (MCC) and regenerated cellulose from ILs after dissolution were characterized using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results clearly revealed that the thermal stability of regenerated cellulose were reduced.

Glycerin/NaOH Aqueous Solution as a Green Solvent System for Dissolution of Cellulose

“…This convinced the good dissolution ability of glycerin/NaOH solvent system to the cellulose. After further adding of HCl, the apparently strip morphology with much smaller size (compared with the cellulose before dissolution) may attribute to the reduced crystallinity which accompanied by increased amorphous area after cellulose regeneration [25].…”

Green Composites from Ionic Liquid-Assisted Processing of Sustainable Resources: A Brief Overview

“…Most of these materials are liquids at ambient or far below ambient temperature and have been widely used as a potential alternative to toxic, hazardous, volatile, and highly flammable organic solvents [1][2][3]. Various unique and attractive physicochemical properties of ILs, such as remarkable thermal and chemical stability [4,5], extremely low vapor pressure [6], high solvation interactions with inorganic and organic compounds [7], broad electrochemical window, and sharp ionic conductivity, make ILs promising candidates for the replacement of volatile organic compounds (VOCs) for polysaccharide dissolution and modification [8].…”