A kind of preparation method of low molecular weight chitosan

Abstract

The invention provides a preparation method of low-molecular weight chitosan. The method comprises a step of degrading high-molecular weight chitosan, wherein before degrading the high-molecular weight chitosan, a protecting group is introduced to perform amino protection on chitosan; and the protecting group is one of carbobenzoxy, t-butylcarbonyl, trimethyl silicon ethoxycarbonyl and fluorenylmethyloxycarbonyl. The high-molecular weight chitosan is degraded through the technology combining short-time ultrasonic and hydrogen peroxide chemical degradation. By adopting the method provided by the invention, the prepared low-molecular weight chitosan has relatively high content of active amino, the molecular weight is low, the molecular weight distribution is relatively narrow, the color is pure white, the yield is high, and the application value is greatly increased; by combining ultrasonic pretreatment and chemical oxidation, the degradation efficiency and the energy utilization rate are improved, and the production cost is greatly reduced; and moreover, the technology is simple and convenient to operate, the reaction is easy to control, the reaction conditions are mild, and the method is suitable for large-scale industrial production.

Description

technical field

[0001] The invention belongs to the technical field of chitosan degradation, and in particular relates to a preparation method of low molecular weight chitosan. Background technique

[0002] Chitin is a six-carbon polymer similar to plant fibers. It is the only biodegradable cationic polymer material that exists in nature. It is widely found in crustaceans such as shrimps and crabs, as well as insects, algae and In bacteria, it is also called animal element, chitin, chitin or chitin. Due to its chemical inactivity and poor solubility, chitin has very limited direct applications. Chitosan (Chitosan), which is obtained after deacetylation of chitin, has greatly changed its chemical properties due to the presence of amino active groups in its molecular structure. It is the only natural alkaline polysaccharide found so far and has many unique properties. It also has the advantages of non-toxicity, good biocompatibility and easy degradation. However, the hydrog...

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