Carboxymethyl cellulose

Химические свойства

Cellulose is a natural substance normally present in most diets because it is the major structural carbohydrate of green plants. Cellulose is essentially a linear polymer of glucopyranose units connected by α-1,4-glucoside links. In nature, cellulose is present in plant cell walls as fibers. The molecular weight of the isolated cellulose is approximately 50,000 daltons. The principal sources of cellulose for food-related purposes are cotton linters and wood pulp.
Chemical processing converts cellulose into forms or derivatives suitable for incorporation into food products or for use in food packaging materials. For food use, the optimum degree of substitution of a carboxymethyl-residue on each anhydroglucopyranose unit on cellulose is 0.95. By preliminary mild acid hydrolysis, the degree of polymerization (i.e., molecular size) of the cellulose may be reduced before carboxymethylation. Control of the degree of substitution and the degree of polymerization during processing results in production of a wide variety of derivatives that differ in such physical properties as gelling, temperature, viscosity and dispersibility in water. Sodium carboxymethyl cellulose is used as a thickening agent and stabilizer in foods. Because carboxymethyl cellulose is spontaneously converted to sodium salt in alkaline solution, it is probable that any distinction between carboxymethyl cellulose and sodium carboxymethyl cellulose in foodstuffs is artificial.*

Использование

carboxymethyl cellulose (cellulose gum) is a thickener. used in cosmetic formulations when a reactant is not required or desired. often used in bath preparations, beauty masks, hand creams, and shampoos. It is considered a non-comedogenic raw material.

Подготовка

Sodium carboxymethyl cellulose is produced by treating wood pulp or cotton linters with alkali and monochloroacetic acid. It occurs as a white- or cream-colored powder or granules.

Промышленное использование

Carboxymethyl cellulose is manufactured with molecular weights ranging from 50,000 to 800,000. Several modifications are of interest to flotation because they display good depressing properties for highly floatable magnesium-bearing minerals. These include sodium salts of phenolphthalein ether cellulose and ethanesulfo cellulose.

Канцерогенность

Sarcomas were produced at the site of repeated subcutaneous injection of aqueous solutions of carboxymethylcellulose. It should be noted, however, that massive doses were given and therefore there must have been considerable local trauma.