Carboxymethyl cellulose, which is also known as CMC, is derived from cellulose by introducing a carboxymethyl group along the cellulose chain. The functional properties of carboxymethyl cellulose depends on the degree of substitution of the cellulose structure. This also allows the molecule to be hydrated, thus becoming soluble. The higher the degree of substitution, the more rapidly it dissolves.
Carboxymethyl cellulose is manufactured by the alkali catalyzed reaction of cellulose with chloroacetic acid. Step 1 is the alkalization of the cellulose molecules. This generates alkali cellulose. The alkali cellulose would then undergo etherification reaction to produce carboxymethyl cellulose.
Carboxymethyl cellulose is used as a viscosity modifier and thickener. The anionic nature of it interact with the positive charges found in protein in acidic conditions, thus stabilizing the low pH dairy beverage. It is used to stabilize emulsions in food product like ice cream to control meltdown, texture and protect against heat shock. Carboxymethyl cellulose is used to improve yield in baking by increasing gas bubble formations. It can control ice crystal growth in frozen desserts and soft-serve ice creams and improve mouth feel, body and texture, thus enhancing the quality of bakery items and frozen desserts. It is used in pet foods as a water binder, gravy thickener and extrusion aid.
It is used as a thickening agent in the pharmaceutical industry
It is used in lubricants, toothpaste, laxatives, diet pills, water based paints, detergents, textile sizing and paper products.