| 摘要 |
PURPOSE:To prepare the title chitin which has a sufficient strength for use as a column packing and is uniform in particle diameters, by N-acetylating granular, porous chitosan to give granular, porous chitin and reacting the product with a cyanogen halide in an alkaline atmosphere. CONSTITUTION:Flaky, high-MW chitosan is heated in an aq. soln. of sodium perborate to give low-MW chitosan. The product is dissolved in an aq. soln. of acetic acid, and the soln. is processed into granular, porous chitosan by, e.g., causing it to fall down through a nozzle into a basic coagulant under pressure. The granular, porous chitosan is then N-acetylated by, e.g., reacting it with acetic anhydride in ethanol to give granular, porous chitin, which is further reacted with a cyanogen halide (e.g. cyanogen bromide) in an alkaline atmosphere to give cyanogen halide-activated granular, porous chitin which is suitable as a carrier for immobilizing enzymes. |
