Introduction
Carboxymethyl cellulose was produced in Germany and then gradually it was introduced to United States of America (U.S.A) and other western countries. Nowadays, the industrial and food grade of this product has worldwide consumption in different industries. Carboxymethyl cellulose or CMC is a white, odorless powder which can be suspensed in water. This substance does not ferment in normal condition. From chemical and physical viewpoint this product is usually utilized instead of starch and other natural water soluble materials (which are relatively expensive) like: sodium alginate, tragacanth gum and gelatin. From economic view point this substance has received special attention in recent years which has resulted in significant developments in the field of technology, quality and application of this product. Due to these developments, nowadays Carboxymethyl cellulose has been utilizing in different industries including: food, pharmacy, detergent, resin, coating, building, adhesive, textile, printing, tile and ceramic, pottery, paper, welding electrode, carpet, mining, oil well, wood, artificial leather, cosmetic and pesticide.
CMC features
CMC can be dissolved in cold and hot water to form a gel. The main reason of using this substance is to increase the viscosity but it also has other roles in the final application. Besides it's thickening effect, this product can keep the colloidal state, increase the adhesion, increase the water retention, and it also acts as a scattering agent, stabilizing agent, suspending agent, emulsifying agent and layer forming agent. Because of various features of CMC, it has been using in different fields.
Important physical parameters of CMC
1- Dissolution
2- Viscosity of solution
3- Surface activity
4- Thermoplastic properties
5- Stability ( toward biological degradation, heat, hydrolysis and oxidation)
Technological reasons for utilizing CMC
1- Small concentration of this substance is needed to reach the desired properties
2- Different grades of CMC can be produced with specialized features in order to meet different needs
3- It is tasteless, odorless and colorless
4- Compared to other unmodified natural products, it has higher resistance to microbes
5- It can keep its features in the variety of conditions
6- It has high solubility even in cold water
7- It has thickening effect
8- It can form a stable suspension
9- It acts as an emulsifier
10- It can form a protective layer
11- It improves rheological properties
12- It inhibits the growth of crystals
13- It prevents coalescencing of compounds containing starch