Carboxymethyl cellulose (CMC) or cellulose gum[1] 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 in its sodium salt form, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.[2] Preparation Carboxymethyl cellulose is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid.[3] The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive.[4] Fabrics made of cellulose – e.g., cotton or viscose (rayon) – may also be converted into CMC.[5] Following the initial reaction, the resultant mixture produces approximately 60% CMC and 40% salts (sodium chloride and sodium glycolate). This product, called technical CMC, is used in detergents.[citation needed] An additional purification process is used to remove salts to produce pure CMC, which is used for food and pharmaceutical applications.[6] An intermediate "semi-purified" grade is also produced, which is typically used in paper applications such