Preparation and Properties of Nanocellulose from Organosolv Straw Pulp
A new process for the production of nanocellulose from selected cellulose-containing natural materials has been developed. The liquefaction reaction, using glycols and mild acid catalysis (methane sulphonic acid), was applied to four model materials, namely cotton linters, spruce wood, eucalyptus wood and Chinese silver grass. The process contains only four steps, the milling, the glycolysis reaction, centrifugation and final rinsing with an organic solvent. The nanocrystalline cellulose recovery was between 56% and 75%. The crystallinity index was greater than that of the starting materials due to the liquefaction of lignin, hemicelluloses and amorphous cellulose. The final product was a stable, highly concentrated nanocrystalline cellulose suspension in the organic medium. The liquid residue, after the liquefaction of the cotton linters contained significant quantities of levulinic acid. Different sugars were identified in the liquid residues that were derived from cellulose and hemicelluloses during the liquefaction reaction.