Water-soluble chitosan derivative and preparation method thereof

The invention discloses a water-soluble chitosan derivative and a preparation method thereof, wherein the chitosan derivative is water-soluble chitosan and is prepared from chitosan and chloroacetic acid through a carboxylation reaction according to a molar ratio of the chloroacetic acid to the hydroxyl on the chitosan of 1:1-5:1. According to the invention, the method is mild in reaction condition, simple and safe to operate and easy to accept by researchers; the chitosan derivative obtained by the reaction has good water solubility; by controlling the reaction time, the molar ratio and otherfactors, the chitosan derivative can be dissolved in deionized water at room temperature, and the water solubility can be greatly changed along with different reaction conditions, so that the application field of chitosan is expanded, and the chitosan has potential application value in the fields of injectable drug sustained-release carriers, heavy metal ion adsorption and the like. 一种水溶性壳聚糖衍生物及其制备方法。该壳聚糖衍生物为水溶性壳聚糖，由壳聚糖和