Carboxymethylcellulose (CMC) 羧甲基纤维素（CMC）

   Natural cellulose is the most widely distributed and most abundant polysaccharide in nature, and its sources are very rich. The current modification technology of cellulose mainly focuses on etherification and esterification. Carboxymethylation is a kind of etherification technology. Carboxymethyl cellulose (CMC) is obtained after carboxymethylation of cellulose. Its aqueous solution has the functions of thickening, film-forming, bonding, water retention, colloid protection, emulsification and suspension, and is widely used in petroleum, food, medicine, etc. , textile and paper industries, is one of the most important cellulose ethers.

    Carboxymethyl cellulose (CMC) is a non-toxic and odorless white flocculent powder with stable performance and is easily soluble in water. Its aqueous solution is a neutral or alkaline transparent viscous liquid, soluble in other water-soluble glues and resins, insoluble in organic solvents such as ethanol. CMC can be used as adhesive, thickener, suspending agent, emulsifier, dispersant, stabilizer, sizing agent, etc.

Carboxymethyl cellulose (CMC) is the product with the largest output, the most widely used and the most convenient use among cellulose ethers, commonly known as "industrial monosodium glutamate".

1. It is used for oil and natural gas drilling, well digging and other projects

① The mud containing CMC can make the well wall form a thin and firm filter cake with low permeability, which reduces the water loss.

② After CMC is added to the mud, the drilling rig can obtain a low initial shear force, so that the mud can easily release the gas wrapped in it, and at the same time, the debris is quickly discarded in the mud pit.

③Drilling mud, like other suspension dispersions, has a certain period of existence, and the addition of CMC can make it stable and prolong the period of existence.

④ The mud containing CMC is rarely affected by mold, so it is not necessary to maintain a high pH value and use preservatives.

⑤ Contain CMC as drilling mud washing fluid treatment agent, which can resist the pollution of various soluble salts.

⑥ The mud containing CMC has good stability and can reduce water loss even if the temperature is above 150℃.

CMC with high viscosity and high degree of substitution is suitable for mud with low density, and CMC with low viscosity and high degree of substitution is suitable for mud with high density. The selection of CMC should be determined according to different conditions such as mud type, region and well depth.

2. Used in textile, printing and dyeing industry. The textile industry uses CMC as a sizing agent for light yarn sizing of cotton, silk wool, chemical fiber, blended and other strong materials;

3. Used in paper industry CMC can be used as paper surface smoothing agent and sizing agent in paper industry. Adding 0.1% to 0.3% CMC to the pulp can enhance the tensile strength of the paper by 40% to 50%, increase the compressive rupture by 50%, and increase the kneadability by 4 to 5 times.

4. CMC can be used as a dirt adsorbent when added to synthetic detergents; daily chemicals such as toothpaste industry CMC glycerin aqueous solution is used as a gum base for toothpaste; pharmaceutical industry is used as a thickener and emulsifier; CMC aqueous solution is thickened and used for floating mineral processing, etc.

5. In the ceramic industry, it can be used as an adhesive, plasticizer, suspending agent for glaze, color fixing agent, etc.

6. Used in construction to improve water retention and strength

7. It is used in the food industry. The food industry uses CMC with high substitution degree as a thickener for ice cream, canned food, quick-cooked noodles, foam stabilizer for beer, etc. For thickeners, binders or excipients.

8. The pharmaceutical industry selects CMC with appropriate viscosity as a tablet binder, disintegrant, and suspending agent for suspensions.