<i>N</i>‐acetylchitosan gel: A polyhydrate of chitin

Abstract

Abstract N ‐Acetylchitosan gel, a polyhydrate of chitin, and partially O ‐acetylated N ‐acetylchitosan gel were produced by a facile acetylation of chitosan with acetic anhydride in 10% acetic acid and in aqueous acetic acid/methanol at room temperature. Under the same conditions, a series of N ‐acylchitosan gels was produced in reaction with the other carboxylic anhydrides. The gels thus produced were colorless, transparent and rigid, and stable on heating. The gels were insoluble in cold and boiling water, formic acid, aqueous acids, and the other solvents examined. Significant changes in specific rotation occurred in the acylation of chitosan and its aggregation.