A system for the production of carboxymethyl chitosan

Abstract

A system for the synthesis of carboxymethyl chitosan, comprising: a reaction medium preparation unit configured to dissolve monochloroacetic acid in deionized water and disperse chitosan into this solution to form a homogeneous reaction medium which is stored in a reaction vessel; an alkalization unit configured to dropwise introduce an alkaline solution into the prepared homogeneous reaction medium which is located in the reaction vessel at a controlled temperature between 15 and 18 °C, wherein the alkalization unit includes a dropwise addition mechanism which enables a slow and dropwise addition of alkaline solution to the reaction medium solution;a sequential treatment unit, consisting of a temperature control system and an agitator connected to the reaction vessel, wherein the temperature control system is configured to allow sequential treatment in which the alkalized homogeneous reaction mixture is subjected to several thermal stages, and wherein the agitator is configured to facilitate mixing and stirring within the reaction vessel; a precipitation unit connected to the reaction vessel, configured to facilitate the addition of pure methanol to the reaction vessel for polymer precipitation; enabling the dropwise addition of glacial acetic acid solution to the reaction vessel to adjust the pH of the homogeneous reaction mixture to neutral;and a post-processing unit connected to the reaction vessel, configured to perform a multi-stage alcohol wash of the polymer with 80% methanol, followed by treatment with 90% ethanol, and to dry the washed polymer at 50-55°C to obtain carboxymethyl chitosan.