Preparation and crystalline analysis of high-grade bamboo dissolving pulp for cellulose acetate

High grade bamboo dissolving pulp for cellulose acetate (named as acetate bamboo pulp) was prepared from bamboo Cizhu (Dendrocalamus affinnis) by oxygen-alkali pulping, xylanase and DMD (an intermediate product of the reaction of oxone with acetone) delignification treatments, and H2O2 bleaching. Its properties and structures were investigated by different analytical techniques, and compared with those of high grade hardwood dissolving pulp for cellulose acetate (named as acetate wood pulp), viscose bamboo pulp, and bamboo fiber for textile. Most of its properties are comparable with those of acetate wood pulp except ash contents and DCM (dichloromethane) extractive that are slightly high. Crystallinifies and crystalline allomorphs of acetate bamboo pulp and the three samples were determined by FTIR spectroscopy, X-ray diffraction and solid state C-13 NMR spectroscopy, and the results obtained by the three methods were coincident. Bamboo cellulose crystalline allomorphs are classified as I-beta-dominant type, and a higher lateral order index and a larger crystallite size for acetate bamboo pulp were found in spite of its crystallinity similar to acetate wood pulp. Different intermolecular hydrogen bond patterns are likely be responsible for the predominant crystalline fibrils in acetate bamboo pulp. (C) 2007 Wiley Periodicals, Inc.