Sodium carboxymethyl cellulose (CMC-Na) is a carboxymethylated derivative of cellulose and is the most important ionic cellulose gum. Sodium carboxymethyl cellulose is usually an anionic polymer compound prepared by reacting natural cellulose with caustic alkali and monochloroacetic acid, with a molecular weight ranging from several thousand to millions. CMC-Na is white fibrous or granular powder, odorless, tasteless, hygroscopic, easy to disperse in water to form a transparent colloidal solution.

1. Basic information

Chinese name
Sodium carboxymethyl cellulose

Foreign name
Carboxymethylcellulose sodium

aka
Carboxymethyl ether cellulose sodium salt, etc.

Category
compound

molecular formula
C8H16NaO8

CAS
9004-32-4

2. Physical and chemical properties

CMC-Na for short, white to pale yellow powder, granular or fibrous substance, strong hygroscopicity, easily soluble in water, and the solution is high viscosity liquid when it is neutral or alkaline. Stable to medicines, light and heat. However, the heat is limited to 80°C, and if heated for a long time above 80°C, the viscosity will decrease and it will be insoluble in water. Its relative density is 1.60, and the relative density of flakes is 1.59. The refractive index is 1.515. It turns brown when heated to 190-205°C, and carbonizes when heated to 235-248°C. Its solubility in water depends on the degree of substitution. Insoluble in acid and alcohol, no precipitation in case of salt. It is not easy to ferment, has strong emulsifying power to oil and wax, and can be stored for a long time.
3. Main application

Widely used in oil industry digging mud treatment agent, synthetic detergent, organic detergent builder, textile printing and dyeing sizing agent, water-soluble colloidal tackifier for daily chemical products, tackifier and emulsifier for pharmaceutical industry, thickener for food industry Thickener, adhesive for ceramic industry, industrial paste, sizing agent for paper industry, etc. It is used as a flocculant in water treatment, mainly used in wastewater sludge treatment, which can increase the solid content of filter cake.

Sodium carboxymethyl cellulose is also a kind of thickener. Due to its good functional properties, it has been widely used in the food industry, and it has also promoted the rapid and healthy development of the food industry to a certain extent. For example, due to its certain thickening and emulsifying effect, it can be used to stabilize yogurt drinks and increase the viscosity of yogurt system; because of its certain hydrophilicity and rehydration properties, it can be used to improve the consumption of pasta such as bread and steamed bread. quality, prolong the shelf life of pasta products, and improve the taste; because it has a certain gel effect, it is conducive to the better formation of gel in food, so it can be used to make jelly and jam; it can also be used as an edible coating film The material is compounded with other thickeners and applied on the surface of some foods, which can keep the food fresh to the greatest extent, and because it is an edible material, it will not cause adverse effects on human health. Therefore, food-grade CMC-Na, as an ideal food additive, is widely used in food production in the food industry.