Preparation of Microcrystalline Cellulose by Liquefaction of Eucalyptus Sawdust in Ethylene Glycol Catalyzed by Acidic Ionic Liquid

Abstract

Microcrystalline cellulose (MCC) was prepared from the residue of the incomplete liquefaction of eucalyptus sawdust; atmospheric liquefaction was carried out using ethylene glycol as the solvent and 1-(4-sulfobutyl)-3-methylimidazolium hydrosulfate as the catalyst. The highest cellulose content in the residue reached 93.9%. The MCC prepared from liquefaction was characterized by various techniques, which included infrared spectroscopy, X-ray diffraction, thermo-gravimetric analysis, and scanning electron microscopy. The results were compared to those of a commercial MCC (cotton linters). The analyses indicated that hemicelluloses and lignin were removed extensively from the MCC produced from the sawdust. The MCC was a cellulose I polymorph with 79.0% crystallinity. The particles were shaped as elongated rods and had good thermal stability. The particle sizes of the produced MCC ranged from 1 µm to 100 µm with a mean of 38.6 µm.