Carboxymethyl cellulose is a water-soluble anionic polymer which is made from cellulose. In general this substance has these features and properties:
1. It can be used as a thickener, glue, stabilizer, emulsifier, viscosity controller and flow agent.
2. It can form a film and it is resistant to oil, wax, grease and other organic solvents.
3. It can be easily dissolved in water.
4. It is safe to be used in biological systems and also food, pharmaceutical and cosmetic industries.
Due to these features and properties this substance has become an appropriate choice for being used in the food, pharmaceutical, cosmetic, papermaking, tile and ceramic, adhesive, resin and welding electrode industry. Based on the wide-ranging application of CMC in different industries, this product can be classified in three main categories:
A) Food and pharmaceutical industry
Food grade CMC which is sometimes called Cellulose Gum, is a cellulose derivative. The cellulose which is utilized for producing this product is mostly derived from cotton or wood. In order to produce carboxymethyl cellulose, in the presence of cellulose, sodium hydroxide is added to sodium mono chloro acetate and after a chemical reaction, CMC is produced.
Carboxymethyl cellulose can be used as an adhesion agent, thickening agent and stabilizer in food industry. For Food and pharmaceutical application, CMC should have a high purity which means that the purity of synthesized substance should be above 99.5 %. In order to reach such purity, high accurate purification processes are needed. Cellulose gum can stay stable in hot water, cold water and even in the temperatures below zero centigrade (of course, for limited time). That is the reason why this substance is being used as a beneficial additive in vast number of high quality food products. In food industry,
B) Industrial
This product has various industrial applications. For industrial purposes, high purity grade is not needed (maximum purity for these grades is 90 percent) and usually they are synthesized with low viscosity (below 1000 centipoise). Among different industries, Textile, Tile, papermaking, detergent, mining, oil well drilling and paint industry have highest consumption of industrial CMC.
C) Sanitary
In sanitary applications, high purified carboxy methylcellulose is needed. This grade of CMC can be used in pharmaceutical and cosmetic industry for different purposes. In these industries, this substance can be utilized as a suspension agent, hue stabilizer, skin protector, uniform dispersing agent, stain remover, thickening agent, stabilizing agent and also as a lubricant agent. This product is also being widely used in producing toothpaste (for taste and gloss), hands cream, shampoo, shaving cream and also drug pills (because of hydrophilic and swelling properties of CMC).
The differences between carboxy methyl cellulose which are mentioned above, are mainly degree of substitutions, viscosity, particle size and some other parameters.
Reference:
AQUALON Sodium Carboxymethylcellulose - Booklet