A kind of preparation method of low viscosity sodium carboxymethyl cellulose

Abstract

The invention relates to a preparation method of low-viscosity sodium carboxymethylcellulose; a sodium carboxymethylcellulose solution is heated to 50 DEG C by means of water bath and then is poured into a reaction vessel, and the pressure intensity in a Venturi tube is adjusted to 0.3 MPa by a pressure gauge; then the sodium carboxymethylcellulose solution in the reaction vessel is divided into two streams to be inputted into the Venturi tube from two opposite inlets by a material pump, and the two streams are knocked in the Venturi tube, then a knocking flow is generated and a cavitation effect is formed; the sodium carboxymethylcellulose solution after cavitation effect flows back to the reaction vessel from an outlet of the Venturi tube; and after the sodium carboxymethylcellulose solution in the reaction vessel is subjected to 30 min circulation cavitation reaction, a low-viscosity sodium carboxymethylcellulose solution is obtained. The preparation method has the advantages of simple equipment, energy saving, high efficiency, lower cost, no need to add strong oxidizing reagents, simple post-treatment operation and the like, and can achieve large-scale industrialized production.

Description

technical field [0001] The invention relates to a method for preparing low-viscosity sodium carboxymethyl cellulose, in particular to degrading high-viscosity food additive-sodium carboxymethyl cellulose by physical degradation to prepare low-viscosity CMC products. Background technique [0002] CMC (sodium carboxymethyl cellulose) is a kind of cellulose ether, which is usually made of short cotton linters or wood pulp, treated with sodium hydroxide and then reacted with sodium chloroacetate. There are usually three preparation methods : Water-borne method, solution method and solvent method, and other plant fibers are also used to prepare CMC. CMC is a kind of cellulose ether produced from cellulose under the action of sodium hydroxide and sodium monochloroacetate. Taking CMC degree of substitution (Degree of Substitution, DS) as an example, the total reaction chemical formula is as follows: [0003] [C 6 h 7 o 2 (OH) 3 ]n + nClCH 2 COOH + 2nNaOH → [C 6 h 7 o 2 (OH...

AI Technical Summary

Problems solved by technology

The biggest problem with this method is that various chemical reagents are added in the reaction process, which increases the difficulty of product separation and purification, and there are many side reactions, which is not conducive to industrial production.

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