Preparation method of oligochitosan

Abstract

The invention relates to a preparation method of oligochitosan. The oligochitosan is prepared through degradation of chitosan under hydraulic cavitation of chitosan solution. The preparation method comprises the following steps: dissolving the chitosan, carrying out hydraulic cavitation and degradation, adding alkali solution into the chitosan solution after degradation to adjust the pH, washing precipitates, carrying out vacuum drying and the like. The process of hydraulic cavitation and degradation comprises the following steps: placing the chitosan solution into a storage tank, maintaining a constant temperature through a circulating water tank, delivering the chitosan solution to a cavitation device for cavitation and degradation through a pump, adjusting the pressure of the upstream inlet with a valve V1, a valve V2, a valve V3 and a valve V4, restoring the pressure and flow of the downstream, monitoring the pressure and flow with a pressure gauge and a flow meter, making the solution after cavitation and degradation flow back to the storage tank, controlling the temperature to be 25-80 DEG C through the circulating water tank, and carrying out the circulating process in the hydraulic cavitation device for 0.5-20 hour(s) until the oligochitosan satisfies the requirements for the relative molecular mass. The method has the advantages of simple and convenient operation, low energy consumption, high efficiency and the like.

Description

technical field [0001] The invention relates to a preparation method of low-molecular-weight chitosan, in particular to a method for degrading high-molecular-weight chitosan into low-molecular-weight chitosan by using a physical method. Background technique [0002] A chitosan produced by deacetylation of chitin has a large molecular weight and a compact crystal structure. It is insoluble in common solvents and can only be dissolved in some acidic media, which makes the application of chitosan very limited. Big restrictions. In addition, studies have shown that the properties of chitosan with different relative molecular weights are very different, and sometimes even show diametrically opposite characteristics. Many specific functions of chitosan can only be manifested when the relative molecular weight drops to a certain level. The oligomeric water-soluble chitosan obtained by degrading chitosan has unique and superior physiological activity and physicochemical properties,...

AI Technical Summary

Problems solved by technology

This heating not only causes waste of energy, but also is not conducive to the treatment of heat-sensitive substances (such as biology, medicine, etc.); another serious problem of ultrasonic cavitation is its directionality and localization

The cavitation effect only occurs in a small area near the ultrasonic generator. Since the cavitation does not undergo overall migration movement, the formation, development and collapse of the cavitation process are limited to this limited area. Therefore, there is energy in ultrasonic cavitation. Low utilization rate, small cavitation effect area, etc., due to the low yield of chitosan by ultrasonic degradation, the production cost is too high, and it is difficult for industrial application

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