Carboxymethyl cellulose sodium salt
[CAS# 9004-32-4]

Identification

• Classification: Biochemical >> Carbohydrate >> Polysaccharide
• Name: Carboxymethyl cellulose sodium salt
• Synonyms: Cellulose carboxymethyl ether sodium salt; CMC sodium salt
• CAS Registry Number: 9004-32-4 (198084-97-8 / 117385-93-0 / 9085-26-1)
• EC Number: 618-378-6
• SMILES: [Na].OC(C(O)C(O)C=O)C(O)CO.OC(=O)C

Properties

• Melting point: 300 °C
• Water solubility: soluble

Safety Data

• Safety Statements: S24/25

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H332
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

Carboxymethyl cellulose sodium salt, commonly referred to as sodium carboxymethyl cellulose (CMC), is a water-soluble polymer derived from cellulose. It was first synthesized in the 1930s by the chemical modification of cellulose using chloroacetic acid. The compound is a derivative of cellulose, a natural polymer found in the cell walls of plants, with the introduction of carboxymethyl groups that enhance its solubility in water and alter its properties, making it useful in a variety of applications.

Sodium carboxymethyl cellulose is most widely used as a thickening agent, stabilizer, and emulsifier in various industries. In the food industry, it is used as a food additive (designated as E466) to improve the texture, consistency, and mouthfeel of products such as sauces, dressings, ice cream, and baked goods. It serves as a gelling agent, helping to control the viscosity and prevent the separation of ingredients in processed foods. It also enhances the stability of emulsions, which is particularly important in products that contain both oil and water phases.

In the pharmaceutical industry, sodium carboxymethyl cellulose is utilized as a binder and disintegrant in tablet formulations. It helps in the controlled release of active pharmaceutical ingredients, ensuring that the medication is absorbed at the correct rate in the body. Additionally, it is used in the production of hydrogels for wound dressings, where its ability to absorb water and form a gel-like structure is beneficial in maintaining a moist environment that promotes healing.

Sodium carboxymethyl cellulose is also employed in the cosmetic and personal care industries, where it functions as a thickener and stabilizer in products such as shampoos, lotions, creams, and toothpaste. In these formulations, it helps to improve the texture, enhance the stability of emulsions, and ensure the even distribution of active ingredients. Its mild nature makes it suitable for use in sensitive skin products, and its ability to retain moisture is an asset in moisturizing formulations.

In the paper and textile industries, sodium carboxymethyl cellulose serves as a sizing agent, improving the strength, smoothness, and printability of paper. It also acts as a finishing agent for textiles, providing fabric softness and enhancing the durability of the material. Additionally, it is used in the production of paints and coatings, where it improves the spreadability and consistency of the product.

The compound is also important in the oil and gas industry, where it is used as a viscosifier in drilling fluids. In this application, sodium carboxymethyl cellulose helps to control the viscosity of the fluid, making it easier to transport drilling cuttings and maintain wellbore stability.

While sodium carboxymethyl cellulose is generally regarded as safe for use in food, pharmaceuticals, and cosmetics, concerns about the potential environmental impact of its production and disposal have led to research into more sustainable production methods. Nonetheless, its wide range of applications across various industries underscores its importance as a versatile and effective material.

The discovery and application of sodium carboxymethyl cellulose highlight its significance as a multifunctional agent used in food processing, pharmaceuticals, cosmetics, and industrial processes. Its ability to modify the properties of water, enhance product stability, and improve texture makes it an invaluable substance in a wide array of formulations.

References

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