Sodium carboxymethylcellulose

Sodium carboxymethylcellulose (also known as CMC or cellulose gum) is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is often used as its sodium salt, sodium carboxymethyl cellulose.

Chemistry

Sodium carboxymethylcellulose is synthesized by the reaction of cellulose with sodium hydroxide, followed by carboxymethylation. The degree of carboxymethylation and the degree of substitution can be controlled to result in a range of products suited to different applications.

Properties

Sodium carboxymethylcellulose is a white to cream-colored powder. It is hydrophilic and can form a viscous, non-gelling solution when dissolved in water. The viscosity of the solution depends on the concentration and the degree of substitution of the cellulose.

Applications

Sodium carboxymethylcellulose has a wide range of applications due to its ability to modify the flow behavior of aqueous systems. It is used as a thickener in food and cosmetics, as a binder in pharmaceuticals, and as a lubricant in oil drilling. In the food industry, it is used in products like ice cream and baked goods to improve texture and stability.

Safety

Sodium carboxymethylcellulose is generally considered safe for consumption. However, like all food additives, it should be used in moderation. Some people may experience mild digestive symptoms if they consume large amounts.

See also

• Cellulose
• Food additives
• Thickening agent