Mercerized linters cellulose:: characterization and acetylation in N,N-dimethylacetamide/lithium chloride

Linters cellulose was subjected to different treatments (mercerization and ionized air) before acetylation with acetic anhydride, in homogeneous medium, using DMAc/LiCl as solvent system. Before derivatization, the treated fibres were characterized by Scanning Electron Microscopy, X-ray diffraction, alpha-cellulose content, Inverse Gas Chromatography and viscosimetry. It was shown that except a decrease in the dispersive surface energy, the treatments induced small changes in the cellulose. The degree of acetylation of these fibers was found to follow a linear behavior with the stoichiometry between acetic anhydride and glucose unit, but this linearity obeyed high rate up to a DS of 2.0. The order of reactivity observed for all samples, C6 > > C2 > C3, confirms the higher reactivity of OH in C6 position, because this group is the least sterically hindered of the anhydroglucose unity. (c) 2005 Elsevier Ltd. All rights reserved.