Method for preparing sodium carboxymethylcellulose by abandoned cotton fabrics

Abstract

The invention discloses a method for preparing sodium carboxymethylcellulose by abandoned cotton fabrics, which includes cleaning, drying and cutting up the abandoned cotton fabrics, placing the abandoned cotton fabrics into a pretreating agent solution for heating and stirring, and filtering out after the abandoned cotton fabrics faded; placing and heating the abandoned cotton fabrics in a sodium hydroxide solution for 45-90 minutes at the temperature from 75 DEG C to 100DEG C until colors of the abandoned cotton fabrics are completely faded, and obtaining celluloses; submerging the celluloses into the sodium hydroxide solution, heating the celluloses for 1.5-2 hours at the temperature from 30 DEG C to 50 DEG C, and then removing the sodium hydroxide solution to obtain alkali celluloses; shredding the alkali celluloses and adding absolute ethyl alcohol and the sodium hydroxide solution; dropwise adding a chloroacetic acid ethanol solution at the temperature from 50 DEG C to 60 DEG C; heating for 80-100 minutes at the temperature from 70 DEG C to 80 DEG C; performing a suction filtration and washing; and adding a phenolphthalein indicator, dropwise adding hydrochloric acid for a neutralization until the solution is colorless, washing 1-2 times, and drying after a suction filtration to obtain a finished product.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing sodium carboxymethyl cellulose by using waste cotton fabrics. Background technique [0002] At present, there are many preparation methods of sodium carboxymethyl cellulose, and each method has its own advantages and disadvantages. 1) The patent application (publication number: CN88101790A) records that rice straw and plant stalks are used as raw materials, and sodium carboxymethyl cellulose is prepared through nearly 15 steps such as storage, pretreatment, and impregnation; since the vegetation also contains lignin , pentose, fat and wax and other organic matter, in order to remove these organic matter, the cooking temperature required by the method is higher, and the cooking time is longer, time-consuming and labor-intensive; Broken paper is used as raw material, and sodium carboxymethyl cellulose is prepared through nearly 13 steps such as p...

AI Technical Summary

Problems solved by technology

1) The patent application (publication number: CN88101790A) records that rice straw and plant stalks are used as raw materials, and sodium carboxymethyl cellulose is prepared through nearly 15 steps such as stockpiling, pretreatment, and impregnation; since vegetation also contains lignin , pentose, fat and wax and other organic matter, in order to remove these organic matter, the cooking temperature required by the method is higher, and the cooking time is longer, time-consuming and labor-intensive; Broken paper is used as raw material, and sodium carboxymethyl cellulose is prepared through nearly 13 steps such as pretreatment, alkalization, and pressure filtration; since the cellulose content in the coated broken paper used as raw material is not high, the purity of the obtained product is not high. High, at the same time, the cost of coating broken paper is relatively high, and the process steps of this method are relatively cumbersome, so the preparation cost of this method is relatively high

3) In the patent application (publication number: CN101768220A), the ground cotton is used as a raw material, and sodium carboxymethyl cellulose is prepared through steps such as removal of impurities, alkalization, etherification; because there are more impurities in the ground cotton as a raw material, For example, sand, stone, cotton shell, and cotton epidermal cornea, the pre-treatment is quite complicated; at the same time, there are many types of organic solvents that need to be used in the preparation process, which makes the post-treatment of the preparation process more cumbersome

At present, the industrial production of sodium carboxymethyl cellulose mostly uses refined cotton linters as raw materials, but the price of cotton linters is high, and a large amount of difficult-to-treat wastewater is generated during the refining process, polluting the environment