Melting point: 300 ° C

Water Solubility: Soluble

Commonly used sodium salt. White flocculent powder, odorless, tasteless, non-toxic. Easily soluble in water to form a transparent colloidal liquid, the solution is neutral. Stable to light and heat. Hygroscopic. Insoluble in acids, cresol, ethanol, acetone, chloroform, benzene, etc., difficult to dissolve in methanol, ethyl ether. Cellulose derivatives with carboxymethyl substituents, cellulose treated with sodium hydroxide to form alkali cellulose, which is then prepared by reacting with monochloroacetic acid. The glucose unit that constitutes cellulose has 3 hydroxy groups that can be replaced, so products with different degrees of replacement can be obtained. The average 1 mmol carboxymethyl per 1 g dry weight is insoluble in water and dilute acid, but can be swollen. Used for ion exchange chromatography. Carboxymethyl pKa is about 4 in pure water and about 3.5 in 0.5mol/L NaCl. It is a weakly acidic cation exchanger. It is usually used for the separation of neutral and basic proteins above pH 4. More than 40% of the hydroxyl groups replaced by carboxymethyl can be dissolved in water to form a stable high-viscosity colloidal solution. Pharmacies use CMC with appropriate viscosity as a adhesive, disintegrant, and suspending agent for suspensions. The food industry uses CMC with high displacement as a thickener for ice cream, cans, instant noodles, and foam stabilizer for beer. Widely used in printing and dyeing, pesticide processing, medicine, papermaking, coatings, ceramics, petroleum, food and other industries as sizing agents, thickeners, emulsifiers, emulsifying stabilizers, binders, film-forming agents, etc.