Technique for producing polyanionic cellulose with high degree of substitution

Abstract

This invention discloses a process for producing highly substituted polyanionic cellulose. The method comprises: (1) adding natural cellulose into ethanol solution of NaOH in a kneading machine, alkalizing for 60 min, adding ethanol solution of chloroacetic acid, stirring, heating to 75-80 deg.C, and keeping the temperature for 60 min for etherisation; (2) cooling to below 35 deg.C, adding 50% NaOH solution, stirring uniformly, alkalizing for 60 min, adding ethanol solution of chloroacetic acid, stirring, heating to 75-80 deg.C, and keeping the temperature for 60 min for etherisation; (3) neutralizing, washing for twice, centrifuging to remove water and alcohol, drying, and pulverizing to obtain the product. The polyanionic cellulose has such advantages as high substitution degree, uniform substituent distribution, high resistance to heat, salt and corrosion, and low water loss, and can be used in the fields of oil well drilling, textile dyeing and food industry.

Description

technical field [0001] The invention belongs to the field of fine chemical production, and relates to a production process of polyanion cellulose with a high degree of substitution, in particular to a process for producing polyanion cellulose with a high degree of substitution by two times of alkalization and etherification. Background technique [0002] The existing multi-solvent method for the production of polyanionic cellulose at home and abroad, that is, using an inert organic solvent as the reaction medium, in a stirred tank or a kneader, the cellulose and the reaction reagent are fully and uniformly mixed in the medium to increase the reaction space between the reactants. The contact area can improve the transfer of reaction heat and improve the efficiency of etherification. in: [0003] Most foreign countries use isopropanol as a solvent and use a large solvent ratio to crush and etherify cellulose pulp. Although it has the advantages of high etherification efficien...

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Problems solved by technology

[0003] Most foreign countries use isopropanol as a solvent and use a large solvent ratio to crush and etherify cellulose pulp. Although it has the advantages of high etherification efficiency, good product substitution and uniformity, there are also differences The price of propanol and other raw materials is relatively high, and the post-processing technology is relatively difficult;

[0004] In China, ethanol is usually used as the reaction medium, with a small solvent ratio, and produced by a kneader. Although it has the advantages of cheap ra

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