Principle carboxymethylcellulose sodium Carboxymethyl cellulose sodium (CMC), is a carboxymethylated derivative of cellulose, also known as cellulose glue, is the most important ionic type of cellulose glue.
The CMC was first made in Germany in 1918 and patented in 1921, and has since been commercially produced in Europe.At that time it was only for crude products and was used as colloids and binders.1936-1941, CMC research, and the patent.During World War II, Germany used CMC for synthetic detergents.Industrial production of the CMC began in IG Farbenindustrie AG, Germany in the 1930s.Since then, the production process, production efficiency and product quality have gradually been significantly improved.In 1947, the FDA in the United States according to the toxicology research proved that CMC on the physiological non-toxic effect, allowing it to be used in the food processing industry as additives, thickening effect.
CMC is widely used for its many special properties, such as thickening, bonding, film formation, water holding, emulsification, and suspension, etc.In recent years, CMC of different qualities have been used in dry industry and in different areas of people’s life. Molecular structural features of the CMC Cellulose is unbranched chain molecules formed by D-pyran glucose binding via 3- (14) -glycoside bonding.Its application is limited by the presence of intra-and intermolecular hydrogen-bonding interactions, where cellulose is insoluble in neither cold water nor dry hot water.Cellulose bilges under alkaline conditions, if through a special chemical reaction, replace the hydroxyl groups at C2 C3 and C6 with other groups to obtain cellulose derivatives, in which 35% of pure cellulose is converted to cellulose ester (25%) and cellulose ether (10%).
CMC is a kind of cellulose, usually with short cotton wool (cellulose content up to 98%) or wood pulp as raw material, through sodium hydroxide treatment and then with sodium chloride acetate (CICH2COONa) reaction, and there are usually two preparation methods: water medium method and solvent method.There are also other plant fibers used to prepare CMC, and new synthesis methods have been constantly proposed. The CMC is an anionic-type of a linear polymer.The glucose that constitute cellulose has three ether-capable hydroxyl groups, so the product has various substitutions, with good acid and salt resistance when above 08.Commodity CMC has food grade and industrial grade, the latter has more reaction by-products.
The actual substitution degree of CMC is generally between 0.4 and 1.5, and the substitution degree of CMC for food is generally 0.6~0.95. The recently revised European legislation allows CMC with DS maximum of 15 for food: the substitution degree increases, and the transparency and stability of the solution are better.Degree of Substitution (DS) determines the nature of the CMC, and the distribution of the substituents also affects the nature of the product.The accurate determination of the DS and substituent distributions is a prerequisite for optimizing the reaction conditions and determining the relationship between the structural properties.The carboxymethyl group can be substituted at positions 2,3, and 6 of the glucose unit (AGU), with eight possible structural units (no substitution)