Sodium Carboxymethyl Cellulose (CMC) Detailed Introduction
Introduction to Sodium CMC
Sodium Carboxymethyl Cellulose (CMC) is an anionic water-soluble polymer derived from cellulose. As one of the most versatile hydrocolloids, this white to off-white powder finds applications across food, pharmaceutical, cosmetic, and industrial sectors due to its exceptional thickening, stabilizing, and water-binding properties.
Preparation of Sodium CMC
The industrial production involves an alkali-catalyzed etherification process where:
- Cellulose reacts with sodium hydroxide (alkalization)
- Chloroacetic acid introduces carboxymethyl groups (-CH₂-COOH)
- The resulting sodium salt is purified and milled into powder
Key parameters like Degree of Substitution (DS) are controlled during synthesis to achieve desired solubility and viscosity profiles.
Structure and Properties
Chemical Structure
CMC features a cellulose backbone with carboxymethyl groups substituted on hydroxyl positions of glucopyranose units. The sodium salt form (C₈H₁₅NaO₈) ensures water solubility while maintaining cellulose’s biodegradable nature.
Physical Properties
- Appearance: White to light yellow powder
- Odor/Taste: Odorless, tasteless
- Solubility: Cold/hot water soluble (insoluble in organic solvents)
- Viscosity (1% solution): 25-8000 mPa·s (DS dependent)
- pH (1% solution): 6.5-8.5
- Moisture Content: <10%
- Purity: ≥99.5% (dry basis)
Key Applications
Food Industry (E466)
- Thickener: Sauces, syrups (0.2-1% concentration)
- Stabilizer: Ice cream, yogurt (prevents ice crystals)
- Emulsifier: Beverage clouding agents
- Fraud Prevention: Authenticity marker in processed foods
Pharmaceuticals
- Tablet binder/disintegrant (5-15% w/w)
- Ophthalmic preparations (artificial tears)
- Wound dressing hydrogel component
Cosmetics
- Toothpaste thickener (0.5-2%)
- Lotion stabilizer
- Shampoo viscosity modifier
Industrial Uses
- Textile sizing agent
- Paper coating additive
- Oil drilling fluid component (controls viscosity)
Technical Specifications by Grade
| Parameter | Food Grade | Pharma Grade | Industrial Grade |
|---|---|---|---|
| DS Range | 0.7-0.95 | 0.8-0.95 | 0.7-0.9 |
| Viscosity (1%) | 500-4000 mPa·s | 1000-8000 mPa·s | 25-6000 mPa·s |
| Heavy Metals | <2 ppm | <1 ppm | <5 ppm |
Why Choose Qingdao ACTA Biotechnology’s CMC?
While specific product data requires confirmation, Qingdao ACTA Biotechnology offers potential advantages:
- ISO-certified production ensuring consistent quality
- Custom DS/viscosity grades through advanced R&D
- Global logistics network for reliable supply
- Technical support for application optimization
Conclusion
Sodium CMC powder serves as a multifunctional additive across industries due to its unique combination of water solubility, non-toxicity, and rheological properties. From enhancing food textures to enabling controlled drug release, this cellulose derivative continues to find innovative applications in science and industry.
CMC FAQs
Is CMC safe for consumption?
Yes, food-grade CMC (E466) is Generally Recognized As Safe (GRAS) by FDA when used within specified limits (typically 0.1-2% in foods).
How does DS affect performance?
Higher DS (≥0.8) improves water solubility and salt tolerance, while lower DS grades offer better acid stability.
References
1.Silva, L.S.; Lima, L.C.B.; Silva, F.C.; Matos, J.M.E.; Santos, M.R.M.C.; Santos Júnior, L.S.; Sousa, K.S.; da Silva Filho, E.C. Dye anionic sorption in aqueous solution onto a cellulose surface chemically modified with aminoethanethiol. Chem. Eng. J.2013, 218, 89–98. [Google Scholar] [CrossRef]