CMC (CARBOXYMETHYL CELLULOSE)

CMC (CARBOXYMETHYL CELLULOSE)

Carboxymethyl cellulose (CMC) or cellulose gum is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. 
Carboxymethyl cellulose (CMC) is often used as its sodium salt, sodium carboxymethyl cellulose.

Carboxymethyl cellulose (CMC) is one of the most promising cellulose derivatives. 
Due to its characteristic surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis process, and likewise many contrasting aspects, Carboxymethyl cellulose (CMC) is now widely used in various advanced application fields, for example, food, paper, textile, and pharmaceutical industries, biomedical engineering, wastewater treatment, energy production, and storage energy production, and storage and so on. 

CAS: 9000-11-7
European Community (EC) Number: 618-326-2

IUPAC Name: acetic acid;2,3,4,5,6-pentahydroxyhexanal
Molecular Formula: C8H16O8

Physical Description: White granular solid
Chemical Classes: Biological Agents -> Polysaccharides

Melting Point: 300

Carboxymethyl cellulose (CMC) is a cellulose derivative that consists of the cellulose backbone made up of glucopyranose monomers and their hydroxyl groups bound to carboxymethyl groups. 
Carboxymethyl cellulose (CMC) is added in food products as a viscosity modifier or thickener and emulsifier. 
Carboxymethyl cellulose (CMC) is also one of the most common viscous polymers used in artificial tears, and has shown to be effective in the treatment of aqueous tear-deficient dry eye symptoms and ocular surface staining. 
The viscous and mucoadhesive properties as well as its anionic charge allow prolonged retention time in the ocular surface. 
Sodium carboxymethylcellulose is the most commonly used salt.

Carboxymethyl cellulose (CMC) is a thickening agent that is made by reacting CELLULOSE (wood pulp, cotton lint) with a derivative of acetic acid (the acid in vinegar). 
Carboxymethyl cellulose (CMC) is also called cellulose gum.

Carboxymethyl cellulose (CMC) is an anionic, water-soluble derivative of cellulose, a linear polysaccharide of anhydro-glucose. 
The repeating units are connected by β-1,4-glycosidic bonds. 
At the molecular level, the major difference between CMC and cellulose is only some anionic carboxymethyl groups (i.e., –CH2COOH) in the CMC structure that replace the hydrogen atoms from some hydroxyl groups present in the pristine cellulose infrastructure. 
CMC was first synthesized in 1918. 

Carboxymethyl cellulose as known as CMC (e466) is actually the sodium salt of carboxymethyl cellulose. 
Carboxymethyl cellulose (CMC) is derived from cellulose, which is made water-soluble by a chemical reaction. 
The water-solubility is achieved by introducing carboxymethyl groups along the cellulose chain, which makes hydration of the molecule possible. 
CMC is used as a viscosity modifier or thickener, and to stabilize emulsions in various products including ice cream. 
CMC is known for its excellent water retaining capacity

CMC is a derivative of cellulose, containing carboxymethyl groups that are generated via the reaction of cellulose with chloroacetate in alkali to produce substitutions in the C2, C3, or C6 positions of glucose units. 
As a result, CMC is water soluble and more amenable to the hydrolytic activity of cellulases. 
CMC is therefore a useful additive to both liquid and solid medium for the detection of cellulase activity, and its hydrolysis can be subsequently determined by the use of the dye Congo red, which binds to intact β-d-glucans. 
Zones of clearing around colonies growing on solid medium containing CMC, subsequently stained with Congo red, provides a useful assay for detecting hydrolysis of CMC and therefore, β-d-glucanase activity. 
The inoculation of isolates onto membrane filters placed on the surface of CMC agar plates is a useful modification of this technique, as the filter may subsequently be removed allowing visualization of clear zones in the agar underneath cellulolytic colonies.

Carboxymethyl cellulose (CMC) is one of the most promising cellulose derivatives. Due to its characteristic surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis process, and likewise many contrasting aspects, it is now widely used in various advanced application fields, for example, food, paper, textile, and pharmaceutical industries, biomedical engineering, wastewater treatment, energy production, and storage energy production, and storage and so on. 

Carboxymethylcellulose (CMC) is an anionic, water-soluble cellulose derivative. 
Solubility of CMC depends on the DP as well as the degree of substitution and the uniformity of the substitution distribution. 
Water solubility of CMC would increase with decreased DP and increased carboxymethyl substitution and substitution uniformity. 
The viscosity of the solution increases with increasing DP and increasing concentration.

CMC is soluble in water at any temperature. Because of its highly hygroscopic nature, CMC hydrates rapidly. 
Rapid hydration may cause agglomeration and lump formation when the CMC powder is introduced into water. 
Lump creation can be eliminated by applying high agitation while the powder is added into the water or preblending the CMC powder with other dry ingredients such as sugar before adding into water.

Due to its high solubility and clarity of its solutions, CMC is commonly used in beverages and beverage dry mixes to provide rich mouthfeel. 
Carboxymethyl cellulose (CMC) is also used in acidified protein drinks to stabilize protein and prevent it from precipitating. 
CMC is also added to syrup and sauce formulations to increase viscosity. 
Bakery is another application where CMC is commonly used to improve the quality and the consistency of the end product. 
In tortilla breads, for example, Carboxymethyl cellulose (CMC) is used to improve the process ability of the dough and the textural properties of the end product, including foldability and rollability.

Uses
Introduction
Carboxymethyl cellulose (CMC) is used in a variety of applications ranging from food production to medical treatments.
Carboxymethyl cellulose (CMC) is commonly used as a viscosity modifier or thickener, and to stabilize emulsions in various products, both food and non-food. 
Carboxymethyl cellulose (CMC) is used primarily because it has high viscosity, is nontoxic, and is generally considered to be hypoallergenic, as the major source fiber is either softwood pulp or cotton linter. 
Non-food products include products such as toothpaste, laxatives, diet pills, water-based paints, detergents, textile sizing, reusable heat packs, various paper products, filtration materials, synthetic membranes, wound healing applications, and also in leather crafting to help burnish edges.

Food science
Carboxymethyl cellulose (CMC) is used in food under the E number E466 or E469 (when it is enzymatically hydrolyzed), as a viscosity modifier or thickener, and to stabilize emulsions in various products, including ice cream.
Carboxymethyl cellulose (CMC) is also used extensively in gluten-free and reduced-fat food products.

CMC is used to achieve tartrate or cold stability in wine, an innovation that may save megawatts of electricity used to chill wine in warm climates. 
Carboxymethyl cellulose (CMC) is more stable than metatartaric acid and is very effective in inhibiting tartrate precipitation. 
Carboxymethyl cellulose (CMC) is reported that KHT crystals, in presence of CMC, grow slower and change their morphology.
Their shape becomes flatter because they lose 2 of the 7 faces, changing their dimensions. 
CMC molecules, negatively charged at wine pH, interact with the electropositive surface of the crystals, where potassium ions are accumulated. 
The slower growth of the crystals and the modification of their shape are caused by the competition between CMC molecules and bitartrate ions for binding to the KHT crystals.

Specific culinary uses
Carboxymethyl cellulose (CMC) powder is widely used in the ice cream industry, to make ice creams without churning or extremely low temperatures, thereby eliminating the need for conventional churners or salt ice mixes.
Carboxymethyl cellulose (CMC) is used in baking breads and cakes. 
The use of CMC gives the loaf an improved quality at a reduced cost, by reducing the need of fat. 
Carboxymethyl cellulose (CMC) is also used as an emulsifier in biscuits. 
By dispersing fat uniformly in the dough, it improves the release of the dough from the moulds and cutters, achieving well-shaped biscuits without any distorted edges. 
Carboxymethyl cellulose (CMC) can also help to reduce the amount of egg yolk or fat used in making the biscuits. 
Use of Carboxymethyl cellulose (CMC) in candy preparation ensures smooth dispersion in flavor oils, and improves texture and quality. 
Carboxymethyl cellulose (CMC) is used in chewing gums, margarines and peanut butter as an emulsifier.

Medical applications
Carboxymethyl cellulose (CMC) is also used in numerous medical applications.

Some examples include:

Device for epistaxis (nose bleeding). 
A poly-vinyl chloride (PVC) balloon is covered by Carboxymethyl cellulose (CMC) knitted fabric reinforced by nylon. 
The device is soaked in water to form a gel, which is inserted into the nose of the balloon and inflated. 
The combination of the inflated balloon and the therapeutic effect of the CMC stops the bleeding.
Fabric used as a dressing following ear nose and throat surgical procedures.
Water is added to form a gel, and this gel is inserted into the sinus cavity following surgery.
In ophthalmology, Carboxymethyl cellulose (CMC) is used as a lubricating agent in artificial tears solutions for the treatment of dry eyes.

In veterinary medicine, Carboxymethyl cellulose (CMC) is used in abdominal surgeries in large animals, particularly horses, to prevent the formation of bowel adhesions.

Research applications
Insoluble CMC (water-insoluble) can be used in the purification of proteins, particularly in the form of charged filtration membranes or as granules in cation-exchange resins for ion-exchange chromatography.
Carboxymethyl cellulose (CMC)s low solubility is a result of a lower DS value (the number of carboxymethyl groups per anhydroglucose unit in the cellulose chain) compared to soluble CMC.
Insoluble Carboxymethyl cellulose (CMC) offers physical properties similar to insoluble cellulose, while the negatively charged carboxylate groups allow it to bind to positively charged proteins.
Insoluble Carboxymethyl cellulose (CMC) can also be chemically cross-linked to enhance the mechanical strength of the material.

Moreover, Carboxymethyl cellulose (CMC) has been used extensively to characterize enzyme activity from endoglucanases (part of the cellulase complex); it is a highly specific substrate for endo-acting cellulases, as its structure has been engineered to decrystallize cellulose and create amorphous sites that are ideal for endoglucanase action.
Carboxymethyl cellulose (CMC) is desirable because the catalysis product (glucose) is easily measured using a reducing sugar assay, such as 3,5-dinitrosalicylic acid.
Using Carboxymethyl cellulose (CMC) in enzyme assays is especially important in screening for cellulase enzymes that are needed for more efficient cellulosic ethanol conversion.

Other uses
In laundry detergents, Carboxymethyl cellulose (CMC) is used as a soil suspension polymer designed to deposit onto cotton and other cellulosic fabrics, creating a negatively charged barrier to soils in the wash solution.
Carboxymethyl cellulose (CMC) is also used as a thickening agent, for example, in the oil-drilling industry as an ingredient of drilling mud, where it acts as a viscosity modifier and water retention agent.

Carboxymethyl cellulose (CMC) is sometimes used as an electrode binder in advanced battery applications (i.e. lithium ion batteries), especially with graphite anodes.
Carboxymethyl cellulose (CMC)'s water solubility allows for less toxic and costly processing than with non-water-soluble binders, like the traditional polyvinylidene fluoride (PVDF), which requires toxic n-methylpyrrolidone (NMP) for processing.
Carboxymethyl cellulose (CMC) is often used in conjunction with styrene-butadiene rubber (SBR) for electrodes requiring extra flexibility, e.g. for use with silicon-containing anodes.

Carboxymethyl cellulose (CMC) is also used in ice packs to form a eutectic mixture resulting in a lower freezing point, and therefore more cooling capacity than ice.

Aqueous solutions of Carboxymethyl cellulose (CMC) have also been used to disperse carbon nanotubes, where the long CMC molecules are thought to wrap around the nanotubes, allowing them to be dispersed in water.

Preparation
Carboxymethyl cellulose is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid.
The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive.
Fabrics made of cellulose e.g. cotton or viscose rayon—may also be converted into CMC.

Following the initial reaction, the resultant mixture produces approximately 60% CMC and 40% salts (sodium chloride and sodium glycolate); this product is the so-called technical CMC, which is used in detergents.
An additional purification process is used to remove salts to produce pure CMC, which is used for alimentary and pharmaceutical applications.
An intermediate "semi-purified" grade is also produced, typically used in paper applications such as the restoration of archival documents.

Structure and properties
The functional properties of CMC depend on the degree of substitution of the cellulose structure [i.e., how many of the hydroxyl groups have been converted to carboxymethylene(oxy) groups in the substitution reaction], as well as the chain length of the cellulose backbone structure and the degree of clustering of the carboxymethyl substituents.

SYNONYMS:

Croscarmellose
CARBOXYMETHYL CELLULOSE
Carboxymethylcellulose
Colloresine
9000-11-7
Carmellose
Almelose
Apergel
Carbose
Duodcel
Thylose
Apeyel
CM-Cellulose
Glycocel TA
acetic acid;2,3,4,5,6-pentahydroxyhexanal
KMTs
7H (carbohydrate)
Cellulose, carboxymethyl ether
Carboximethylcellulosum
Carboxymethylcellulosum
Celluloseglycolic acid
Croscarmellosum [Latin]
Cellulose carboxymethylate
Carmellosum [INN-Latin]
Carmelosa [INN-Spanish]
CMC-4LF
Cellulose, (carboxymethyl)
Carboxymethyl cellulose ether
Croscarmellosum [INN-Latin]
Croscarmelosa [INN-Spanish]
Glycolic acid cellulose ether
FEMA No. 2239
Cellulose CM
Cellulose, ether with glycolic acid
Acetic acid, hydroxy-, cellulose ether
7H
Carboxymethylcellulose cellulose carboxymethyl ether
Carmellosum
Croscarmellosum
Croscarmelosa
Carmelosa
Carmellose [INN]
Intrasite gel (TN)
.Carboxymethylcellulose
Croscarmellose (INN)
UNII-05JZI7B19X
SCHEMBL177710
Carmellose (JP17/NF/INN)
05JZI7B19X
LS-3232
FT-0623543
D07622
Q411030
191616-54-3
196886-89-2