Sodium carboxymethyl cellulose (CMC) is an anionic, straight chain, water-soluble cellulose ether, a derivative of natural cellulose and chloroacetic acid by chemical modification. Its aqueous solution has the functions of thickening, film forming, bonding, water retention, colloidal protection, emulsification and suspension, and can be used as flocculant, chelating agent, emulsifier, thickener, water retaining agent, sizing agent, film forming material, etc., which is widely used in food, medicine, electronics, pesticides, leather, plastics, printing, ceramics, daily chemical industry and other fields.

Sodium carboxymethyl cellulose is generally a powdered solid, sometimes granular or fibrous, white or light yellow in color, no special odor, is a macromolecular chemical substance, has a strong wettability, can dissolve in water, in water to form a viscous solution with high transparency. Insoluble in general organic solutions, such as ethanol, ether, chloroform and benzene, but can be dissolved in water, directly dissolved in water is relatively slow, but the solubility is still very large, and the aqueous solution has a certain viscosity. Solid in the general environment is more stable, because it has a certain water absorption and humidity, in a dry environment, can be preserved for a long time.

① Production process

1. Water medium method

The water-coal process is a relatively early production process in the industrial preparation of sodium carboxymethyl cellulose. In this process, the alkali cellulose and etherifying agent react in an aqueous solution containing free oxygen oxide ions, and water is used as the reaction medium in the reaction process, without organic solvents.

2. Solvent method

Solvent method is organic solvent method, which is a production process developed on the basis of water medium method to replace water with organic solvent as a reaction medium. A process of alkalization and etherification of alkali cellulose and monochloroacetic acid in an organic solvent. According to the amount of reaction medium, it can be divided into kneading method and swimming slurry method. The amount of organic solvent used in the pulping method is much larger than that of the kneading method, and the amount of organic solvent used in the kneading method is the ratio of the volume weight of the cellulose amount, while the amount of organic solvent used in the pulping method is the ratio of the volume weight of the cellulose amount. When sodium carboxymethyl cellulose is prepared by swimming slurry method, the reaction solid is in a slurry or suspension state in the system, so the swimming slurry method is also called the suspension method.

3. Slurry method

Slurry method is the latest technology to produce sodium carboxymethyl cellulose. Slurry method can not only produce high purity sodium carboxymethyl cellulose, but also produce sodium carboxymethyl cellulose with high substitution degree and uniform substitution. The production process of slurry method is roughly as follows: the cotton pulp that has been ground into powder is sent to the vertical alkalizing machine equipped with isopropyl alcohol, and the sodium hydroxide solution added while mixing is alkalized, and the alkalizing temperature is about 20℃. After alkalization, the material is pumped to the vertical etherifying machine, and the isopropyl alcohol solution of chloroacetic acid is added, and the etherifying temperature is about 65℃. According to the specific product use and quality requirements, the alkalization concentration, alkalization time, the amount of etherifying agent and etherification time and other process parameters can be adjusted.

② Application scope

1. CMC is not only a good emulsifying stabilizer and thickener in food applications, but also has excellent freezing and melting stability, and can improve product flavor and extend storage time.

2. In the detergent, CMC can be used as an anti-fouling redeposition agent, especially for the hydrophobic synthetic fiber fabric anti-fouling redeposition effect, significantly better than carboxymethyl fiber.

3. In oil drilling can be used to protect oil Wells as mud stabilizer, water retention agent, the amount of each oil well is 2 ~ 3t shallow Wells, deep Wells 5 ~ 6t.

4. Used in the textile industry as sizing agent, printing and dyeing slurry thickener, textile printing and stiffening finish.

5. Used as coating anti-settling agent, emulsifier, dispersant, leveling agent, adhesive, can make the solid part of the paint evenly distributed in the solvent, so that the paint is not stratified for a long time, but also used in putty.

6. As a flocculant in the removal of calcium ions than sodium gluconate more effective, as a cation exchange, the exchange capacity of up to 1.6ml/g.

7. In the paper industry used as paper sizing agent, can significantly improve the dry strength and wet strength of paper and oil resistance, ink absorption and water resistance.

8. As a hydrosol in cosmetics, used as a thickening agent in toothpaste, its dosage is about 5%.

Wholesale Carboxymethyl Cellulose（CMC） Manufacturer and Supplier | EVERBRIGHT (cnchemist.com)