Carboxy methyl cellulose (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.
It is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid. The polar (organic acid) carboxyl

groups render the cellulose soluble and chemically reactive. The functional properties of CMC depend on the degree of

substitution of the cellulose structure (i.e., how many of the hydroxyl groups have taken part in the substitution reaction),

as well as the chain length of the cellulose backbone structure and the degree of clustering of the carboxymethyl

substituents   /