| 摘要 |
PURPOSE:To obtain colorless and odorless low-MW chitosan soluble in neutral water, by treating chitosan with an aqueous solution containing sodium chlorite and hydrogen peroxide in specified concentrations. CONSTITUTION:High-molecular weight chitosan (A) of a mol.wt. of 300,000-1,000,000, obtained by deacetylating natural chitin, is mixed with 10-50 pts.wt., per pt.wt. component A, water (B), and the mixture is heated to 50-98 deg.C. Sodium chlorite (C) in an amount to given a concentration of 0.04-10% and hydrogen peroxide (D) in an amount to give a concentration of 0.04-10% are added to this mixture, and the pH of the resulting mixture is adjusted to 8 or below by the addition of an acid (E). This mixture is subjected to mol.wt. MW-lowering reaction for 30-120min, and sodium borohydride (F) is optionally added to the system in an amount to give a concentration of 0.001-0.05%. |
