Carboxymethyl cellulose CMC
Carboxymethyl cellulose CMC
Carboxymethyl cellulose CMC has the appearance of white or slightly yellow flocculent fiber powder or white powder. It is easily soluble in cold or hot water to form a colloid. The solution is neutral or slightly alkaline. It is insoluble in organic solvents such as ethanol, ether, isopropanol, acetone, etc. It is soluble in ethanol or acetone solutions containing 60% water. It is hygroscopic, stable to light and heat, and the viscosity decreases with increasing temperature. The solution is stable at pH 2-10. When the pH is lower than 2, solids precipitate. When the pH is higher than 10, the viscosity decreases. The color change temperature is 227℃, the carbonization temperature is 252℃, and the surface tension of 2% aqueous solution is 71mn/n.
Uses:
Sodium carboxymethyl cellulose (CMC) is a product with large output, wide application, and convenient use among cellulose ethers. It is commonly known as "industrial MSG".
The important characteristics of CMC are the formation of high-viscosity colloids, solutions, adhesion, thickening, flow, emulsification and dispersion, shaping, water retention, protective colloids, film forming, acid resistance, salt resistance, suspension, etc., and physiologically harmless, so it is widely used in the production of food, medicine, daily chemicals, petroleum, papermaking, textiles, construction and other fields.
1. Application of architectural decoration: spraying on whitewash, spraying lime slurry, mixing gypsum putty, mixing cement putty, talcum powder putty, 821 putty powder, imitation porcelain putty, paint spraying, rolling, spraying, brushing, art finishing, plastering, wallpapering, wall cloth, floor tiles, ceramic tiles, ceramic mosaics, etc.
2. Application in synthetic detergent and soap industry: CMC is a good active additive for synthetic detergents. It is mainly used in detergents to utilize its emulsification and protective colloid properties. During the washing process, it produces anions that can make the surface of the washed object and the dirt particles both negatively charged. In this way, the dirt particles have phase separation in the water phase and repel the surface of the solid phase washed object, so it can prevent dirt from re-depositing on the washed object, which can keep the whiteness of white fabrics and the color of colored fabrics bright. In addition to the above effects, it also has a stabilizing effect, so that the detergent does not precipitate.
3. Application in engineering mud such as oil drilling: In drilling and oil drilling projects, good mud must be prepared to ensure the normal operation of drilling. Good mud must have appropriate specific gravity, viscosity, thixotropy, water loss and other values. These values have their own requirements depending on the region, well depth, mud type and other conditions. Using CMC in mud can adjust these physical parameters, such as reducing water loss, adjusting viscosity, increasing thixotropy, etc.
4. Application in the textile printing and dyeing industry. In recent years, the textile industry has widely used CMC instead of starch as a sizing agent. Practice has proved that CMC sizing not only saves a lot of food and oil, but is also much better than starch, animal glue, etc.
(1) Significantly improves the brightness of printing. Since the general sizing agent is water-based, CMC has strong hygroscopicity, so it can increase the color absorption rate and improve the brightness.
(2) Good permeability. CMC sizing has better permeability than starch sizing, especially for fabrics that need to be deep and transparent, such as georgette embossing, which not only absorbs deep and transparent colors, but also reduces labor intensity.
(3) Easy to desizing, soft texture.
(4) Improve the stability of color paste. CMC is not easy to mold and deteriorate, so the color paste is more stable than starch.
(5) Strong adhesion.