New Hemicellulose-Based Hydrogels

摘要

Different kinds of hemiceilulose-based hydrogels have been made by radical polymerization using hydrosoluble hemicellulose from spruce chips with a number-average molecular weight and polydispersity of 2400 and 1.5 respectively. 80% of the hemicellulose was galactoglucomannan and the remainder mainly 4-O-methylglucuronoxylan. Hemicellulose/poly(2-hydroxyethyl methacrylate) based hydrogels were prepared by polymerization in water of 2-hydroxyethyl methacrylate with hemicellulose modified with well-defined amounts of methacrylic functions. The chemical modification of hemicellulose was performed in dimethyl sulfbxide using 2-[(1-imidazolyl) formyloxy]ethyl methacrylate as modifying agent. The kinetics of the modification reaction were monitored by ~1H NMR. The degree of modification of the hemicellulose used for the hydrogel synthesis varied from 10% to 40%. The ratio of modified hemicellulose to 2-hydroxyethyl methacrylate in the hydrogels was 1:1 by weight. The resulting hydrogels were elastic, homogeneous, soft, transparent and easily swollen in water.