Title: Carboxymethylcellulose Sodium
CAS Registry Number: 9004-32-4
CAS Name: Carboxymethyl ether cellulose sodium salt
Additional Names: sodium carboxymethylcellulose; sodium cellulose glycolate
Trademarks: Cethylose (Ascher); CMC (Stuart); Cel-O-Brandt; Glykocellon; Carbose D; Xylo-Mucine; Tylose MGA; Cellolax; Polycell
Line Formula: RnOCH2COONa
Literature References: Prepd by treating alkali cellulose with sodium chloroacetate: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 235-238. Review and bibliography: Ott, Cellulose and Cellulose Derivatives, New York, 1946 (2nd ed., 1955).
Properties: White granules. Soly in water depends on degree of substitution. Water-soluble CMC is available in various viscosities (5-2000 cP in 1% soln), and the soly is equally good in hot and cold water (difference from methyl cellulose). Also the presence of metal salts has little effect on the viscosity. Solns are stable between pH 2 and 10. Below pH 2 precipitation of a solid occurs, above pH 10 the viscosity decreases rapidly. pKa 4.30. The free acid is obtained from aq soln at pH 2.5 and may be precipitated with alcohol.
pKa: pKa 4.30
Use: In drilling muds, in detergents as a soil-suspending agent, in resin emulsion paints, adhesives, printing inks, textile sizes, as protective colloid in general. As stabilizer in foods. Pharmaceutic aid (suspending agent; tablet excipient; viscosity-increasing agent).