Carboxymethyl Cellulose (English: Carboxymethyl Cellulose, CMC for short) is a commonly used food additive, and its sodium salt (sodium carboxymethyl cellulose) is often used as a thickener and paste.
Carboxymethyl cellulose is called industrial monosodium glutamate, which is widely used in industrial production and brings great use value to various production fields. Carboxymethyl cellulose is a powdery substance, non-toxic, but it is easy to dissolve in water. It is soluble in cold water and hot water, but it is insoluble in organic solvents. It will become a viscous liquid after dissolving, but the viscosity will vary due to temperature rise and fall. Due to its special properties, there are many special requirements in storage and transportation.
Physical and chemical properties
Carboxymethyl cellulose is a white or light yellow substance, odorless, tasteless, hygroscopic granules, powder or fine fibers.

preparation
Carboxymethylcellulose is synthesized by the base-catalyzed reaction of cellulose with chloroacetic acid. Polar (organic acid) carboxyl groups make cellulose soluble and chemically reactive. After the initial reaction, the resulting mixture yielded approximately 60% CMC plus 40% salts (sodium chloride and sodium glycolate). The product is a so-called industrial CMC for detergents. These salts are removed using a further purification process to produce pure CMC for use in food, pharmaceuticals and dentifrices (toothpaste). Intermediate “semi-purified” grades are also produced, often used in paper applications such as the restoration of archival documents. The functional properties of CMC depend on the degree of substitution of the cellulose structure (that is, how many hydroxyl groups participate in the substitution reaction), as well as the chain length of the cellulose backbone structure and the degree of aggregation of the cellulose backbone. Carboxymethyl substituent.

application
Carboxymethylcellulose is used in food as a viscosity modifier or thickener under the E number E466 or E469 (by enzymatic hydrolysis) and to stabilize emulsions in various products, including ice cream. It is also a component of many non-food products such as toothpaste, laxatives, diet pills, water-based paints, detergents, textile sizing agents, reusable thermal packaging and various paper products. It is used primarily because it is high viscosity, non-toxic and generally considered hypoallergenic since the main source fibers are softwood wood pulp or cotton linters. Carboxymethylcellulose is widely used in gluten-free and reduced-fat foods. In laundry detergents, it is used as a soil suspending polymer designed to deposit onto cotton and other cellulosic fabrics, creating a negatively charged barrier to soils in the wash liquor. Carboxymethylcellulose is used as a lubricant in artificial tears. Carboxymethylcellulose is also used as a thickening agent, for example, in the oil drilling industry, where it is a component of drilling mud, where it is used as a viscosity modifier and water retention agent. For example, sodium CMC (Na CMC) was used as a negative control for hair loss in rabbits. Knitted fabrics made from cellulose, such as cotton or viscose rayon, can be converted into CMCs and used in various medical applications.