Carboxymethyl Cellulose

Everything You Need to Know about Carboxymethyl Cellulose

Carboxymethyl cellulose (CMC) is a cellulose compound which is widely used in the construction industry. A carboxymethyl cellulose polymer is useful in the construction industry as a dispersant, stabilizer, and thickener, which are crucial properties for a long-lasting construction project.

The reason for the popularity of the application of carboxymethyl cellulose is that it enhances several properties of the cement mix, such as durability, strength, setting time, and workability.

What is Carboxymethyl Cellulose?

Carboxymethyl cellulose is also called cellulose gum in common terms. It is a cellulose derivative with certain carboxymethyl groups connected to some glucopyranose monomers’ hydroxyl groups to form the base of the cellulose. CMC is a water-soluble, anionic cellulose derivative.

The solubility of CMC is determined by the substitution distribution’s uniformity and the degree of substitution. In addition, its solubility also depends on the DP, as decreased DP along with increased carboxymethyl substitution and substitution uniformity cause the CMC’s water solubility to increase. As the concentration of the solution and DP increases in the solution, the solution’s viscosity also grows.

Carboxymethyl cellulose polymer is readily soluble in water. CMC hydrates quickly as it is hygroscopic in nature. When mixed with water, the carboxymethyl cellulose powder rapidly hydrates.

This swift hydration results in agglomeration and development of clumps. However, if high agitation is applied when adding the powder to the water, the clumps can be avoided successfully.

How is Carboxymethyl Cellulose prepared?

Carboxymethyl cellulose is synthesized by the alkali-induced reaction of cellulose with chloroacetic acid. Cellulose contains organic acid-based carboxyl groups which are polar and chemically reactive.

During the initial reaction, around 40% of salts and 60% of CMC is produced in the resultant compound. The product derived in this stage is useful in detergents and is popularly known as the Technical CMC.

For pure CMC, an additional purification process is performed to remove salts. This pure CMC is mostly used in food and pharmaceuticals applications.

At the same time as this, another process takes place, which produces an intermediate and unpurified grade CMC. This unpurified grade CMC is mainly used in paper-based applications, such as restoring archival documents.

There are three main components that determine the functional characteristics of carboxymethyl cellulose – the cellulose backbone structure’s chain length, how many hydroxyl groups participate in the substitute reaction, and the degree of clustering of the carboxymethyl substitute.

What is the Source of Carboxymethyl Cellulose?

Carboxymethyl cellulose is usually extracted from cellulose, which is a simple polymer based on sugar and present in plants.

The process of procuring carboxymethyl cellulose has 2 steps –

  1. The first step is to create a cellulose suspension in an alkaline medium. The suspension opens the chains of cellulose, which in turn, allow the water to enter within.
  2. After successful suspension the cellulose can react with sodium mono-chloroacetate and give sodium carboxymethyl cellulose.

How Carboxymethyl Cellulose helps Develop Solid Polymer Electrolytes?

There has been widespread research going on for a new electrolyte for electromechanical applications. Three decades of intense studies and development have given us a revolutionary polymer electrolyte system.

Wright first discovered ionic conductivity in a PEO/Na+ complex in 1975. This caused a growth in focus on Solid Polymer Electrolytes (SPE), particularly directed towards improving ionic conductivity.

As compared to liquid and gel polymer electrolytes, SPE has several advantageous properties. Carboxymethyl cellulose solid polymer electrolytes are quite flexible, have low self-discharge when used in batteries, do not leak, are easy to fabricate and highly compatible with other electrolytes.

Owing to their significant mechanical and electrical characteristics, research has been largely focused on obtaining polymer electrolytes more efficiently. For example, numerous studies were conducted on sustainable extraction of polymer electrolytes from natural sources like starch and cellulose derivatives.

The studies have focused on obtaining polymer electrolytes from hydroxyl ethyl cellulose (HEC), methylcellulose (MC), carboxymethyl cellulose (CMC).

CMC shows the greatest potential as an efficient source of solid polymer cellulose as it shows amphiphilic characteristics. It is one of the most common organic substances on earth that also has a base of hydrophobic polysaccharides and numerous hydrophilic carboxyl groups.

Let’s learn in-depth about SPE –

Carboxymethyl Cellulose

Solid Polymer Electrodes

Earlier, CMC-based solid polymer electrolytes had to be created and grew on a thin see-through membrane. At 303 K (room temperature), the OA2O sample possessed the highest ionic conductivity, at 2.11 x 10-5 S cm-1. According to the Dielectric study, the samples also displayed non-Debye behavior.

The study also showed that the sample showed more activation energy at relaxation than it did at conduction. This implied that the charge carrier was able to penetrate the higher energy limits while relaxing and conducting.

Organic Cellulose

Cellulose is one of the most abundant organic materials on our planet. It is an integral part of every single plant on earth. It is also a material that has been commonly used in the textile and packaging industry for years.

Carboxymethyl cellulose (CMC) is one of the widely used commercial cellulose-based ether and is a simple cellulose derivative with sodium carboxymethyl group substitution. It is an excellent alternative to many hydroxyl groups with glucopyranose monomers.

The cellulose base is constructed from glucopyranose monomers’ hydroxyl groups, while its frame is cellulose’s (1->4)-d-glucopyranose polymer. Different preparations have different degrees of substitution. However, normally, the substitution ranges between 0.6 to 0.95 derivative, per monomer unit.

Carboxymethyl cellulose has numerous applications. These include being used as a commercial –

  • Binder
  • Stabilizer
  • Film-forming solution
  • Thickener
  • Rheology control agent

Thanks to its multipurpose characteristics, CMC is very useful in the following industries –

  • Construction
  • Cosmetics
  • Pharmaceuticals
  • Food processing
  • Textile
  • Adhesives
  • Oil drilling fluids

Current developments have allowed scientists to graft polymerized vinyl and acryl monomers into a cellulose frame. Once the monomer is successfully grafted, some of the drawbacks from the cellulose are eliminated, such as low tensile strength, high moisture transmission, and microbial degradation.

Graft Copolymers

The structure of graft copolymers has a single long polymer’s sequence (backbone polymer), with one or multiple grafts (branches) of other polymers that are chemically different from one another. The graft copolymer begins synthesizing with a pre-formed polymer, which is polysaccharide in the case of grafted polysaccharide.

The pre-formed polymer begins creating free radical sites with the help of an external agent. This agent should be sufficient and effective enough to form the required free radical sites on the pre-formed polymer.

Simultaneously the external agent should not be too rough that it may break the pre-formed polymer chain’s structure. The grafted chains then begin to form on the vinyl or acrylic compound monomer when it is added during the chain propagation phase.

Graft copolymers can also be synthesized using several different methods, and there is significant difference in the formation process of free radical sites on the pre-formed polymer.

Generally, this is commonly done using chemical-free radical initiators, or high energy radiation from gamma rays or electron beam, or with ultraviolet rays over a photosensitizer.

Previously, researchers discovered the most efficient technique to synthesize graft copolymers is by using microwave radiations to initiate the grafting reaction. The microwave radiation selectively excites only the polar bonds which causes them to rupture and results in producing free radical sites.

C-C Backbone

Microwave radiation does not affect the pre-formed polymer’s C-C backbone because it is virtually non-polar. There are significant benefits of using synthesis techniques like microwave-based synthesis of graft copolymers.

For instance, this type of synthesis process is fast, simple, highly reproductible and gives greater control of the grafting percentage. Besides this, these grafting techniques do not require any inert atmosphere, unlike other conventional techniques of grafting copolymers.

In essence, the microwave-based technique of synthesizing graft copolymers is the most efficient method, which has the potential to be easily commercialized.

Synthesis of CMC-g-PAA by Microwave Initiated Method

Microwave-initiated method to synthesize graft copolymers also synthesizes CMC-g-PAA. This is achieved with slight variations in the frequency of microwave radiation and the concentration of acrylic acid monomer, while synthesizing graft copolymer of varying types.

The level of monomer and duration of the radiation blasts optimizes the synthesizing process. This step also determines the grade of the graft copolymer according to the percentage of grafting and its inherent viscosity.

Usually, the irradiation is performed for 5 minutes on a monomer with a 10-gram acrylic concentration, with the microwave power at 800W. This step generates heat when the microwave radiation irradiates polar molecules, such as water and rotates the complete molecule at the same time. No free radicals are formed because of the breaking of the bonds as the whole molecule rotates.

Polysaccharides Solution

Though there is no response in the non-polar C-C bonds when the macro-molecules, such as polysaccharides, are irradiated with microwave radiation, the O-H polar bonds rotate in response.

The molecules individual rotation breaks the polar bond which helps to form free radical sites. Hence, the polar bonds are selectively excited by microwave radiation, which is not seen with high energy radiation and thermal energy bombardment. As the C-C bonds are not affected by the radiation, the backbone polymer’s structural integrity remains strong.

Once the free radical sites are formed on the backbone polymer film, the chain propagation process is used to add the monomer. This is done until the free radical sites are terminated with the chain termination steps

What are the Functions of Carboxymethyl Cellulose?

There are several different functions of carboxymethyl cellulose. These CMC functions are mainly dependent on the following factors –

  • Carboxymethyl cellulose’s chain reaction
  • Cellulose’s backbone
  • Volume of carboxymethyl cellulose and substitution of sodium ions

For instance, carboxymethyl cellulose with homogenous substituent has better flow potential. However, carboxymethyl cellulose with non-homogeneity replacement is called thixotropic. CMC produces a stiff gel that becomes significantly extra fluid when it is disturbed and eventually enhances the intrinsic properties of the gel.

CMC has multiple excellent characteristics which is why it is being widely used in the construction industry today. Below are some of the major functions of carboxymethyl cellulose in the field of construction –

Cement mortar

Use of carboxymethyl cellulose can enhance the dispersal of sand and cement in the mortar. This remarkably improves the plasticity and water-retention properties of the mortar. Hence, it can effectively prevent cracks from developing and enhance the overall strength of the cement mix.

Ceramic tile cement

The application of carboxymethyl cellulose improves the plasticity and water-retention of pressed ceramic tile mortar. This helps to enhance the bond stress of ceramic tile and prevents deterioration and damage to the tiles.


CMC also acts as a substitute for natural adhesive paste. It improves water-retention in mortar which strengthens the bond between the substrate and wall finish.

Fiber Wall

Carboxymethyl cellulose is also a great adhesive for sand walls, with excellent anti-bacterial and anti-mildew properties.

Emulsion Putty

CMC also improves the fluidity of emulsion-based putty and enhances its water retention properties significantly, making it easier to apply and achieve superior finish.

Fire-Resistant Coatings

Carboxymethyl cellulose is an excellent suppression agent. It not only improves the flowability of asbestos and other fire-resistant coatings but also provides excellent bonding strength to the substrate.

Gypsum concrete pulp

Carboxymethyl cellulose polymer is effective in enhancing water retention in gypsum concrete pulp and improving processability.


CMC is also an excellent plasticizer for latex-based paints. It enhances the fluidity of paint and putty powder, which in turn improves the paint’s performance.

Joint cement

Carboxymethyl cellulose compound is often added to joint filling cement, usually used in gypsum board to enhance water retention and fluidity.

Secondary cement products

CMC also acts as a press molding binder for asbestos and cement pre-cast products. It helps to enhance the fluidity of asbestos and cement, making it easier to achieve uniformity in products during the molding process.

What effect does Carboxymethyl Cellulose have on Cement Properties?

Carboxymethyl cellulose is used as a dispersant, thickener and stabilizer. It is a key component of cement and widely used in the construction industry. Carboxymethyl cellulose use in cement enhances several of its properties, such as durability, setting time, strength, and workability.

Below are the properties of cement that get enhanced with application of carboxymethyl cellulose –

Setting Time

Carboxymethyl cellulose works as a retarder in cement mixes. It slows down the hydration process and extends the hardening time of the cement. This is highly helpful when extra hours are needed to work on cemented surfaces and concrete components.

Additionally, slow setting time is very useful in large-scale construction projects and in hot weather conditions where there is a risk of the cement hardening in less time than it normally takes.


The role of carboxymethyl cellulose is vital to increase flowability of cement. CMC effectively enhances the fluidity of cementitious materials. When CMC is added to concrete mixtures, it works as a water-reducing agent as it allows the cellulose particles to be properly dispersed.

This, in turn, increases the fluidity which improves the overall workability of cement. The increased flowability also makes it easier to transport, handle and place the cement mix.


Carboxymethyl cellulose polymer also ensures higher durability by improving the concrete’s resistance to freeze-thaw cycle. By improving the dispersion of cellulose particles and water in the cement mixture carboxymethyl cellulose helps minimize the damage by expansion of water in freezing temperatures. This way, the CMC improves durability of concrete structures.


Early strength improvement is another important role of carboxymethyl cellulose. Though CMC can extend the hardening time of cement, it also significantly contributes to early strength development of the concrete. This is especially beneficial when quick strength gains are needed but without affecting the long-term strength.


Carboxymethyl cellulose powder also enhances adhesion of some construction compounds. CMC has significant adhesive properties that make the bond between cement particles and aggregates extremely strong. This better adhesion improves the overall bonding strength of concrete mixtures, which results in creating bigger and better structures.


CMC also reduces the risk of cracks in cement that occur due to unwanted shrinkage. Adding carboxymethyl cellulose to cement effectively reduces shrinkage of the cement surface, which in turn, prevents shrinkage cracks from developing. This also enhances the long-term durability of concrete.

Water Retention

Carboxymethyl cellulose products also help to increase the water retention in cement mixes. CMC is known for its water-retaining properties which prevents rapid loss of water from concrete. This property is highly helpful in situations where a specific moisture quantity is needed for ideal hydration and to develop high strength concrete.


The use of carboxymethyl cellulose in cement mixtures can also be a cost-effective solution. Mixing CMC with cement can optimize hybrid design and achieve the grade of performance you need without using expensive alternatives.

What are the Effects of Carboxymethyl Cellulose (CMC) in Dry Mortar in Construction?

Carboxymethyl cellulose is an ionic ether. It is made after several sequential reactions from natural fibers, once the fibers have been treated with alkali. Besides this, sodium mono-chloroacetic acid is used as an etherifying agent in the production of CMC.

Let’s check the effects of carboxymethyl cellulose in dry mortar in construction –


Carboxymethyl cellulose is significantly hygroscopic. It contains a higher quantity of water during storage at normal conditions.


The aqueous compound obtained from carboxymethyl cellulose does not produce gels. Increasing temperatures result in lowering the viscosity of the cellulose compound. For instance, when the temperature is over 50-degrees Celsius, the viscosity of the gel cannot be reversed.


The stability of mortar is also affected by the mean pH value. Usually, carboxymethyl cellulose can be used in gypsum-laced mortar, but it can also be easily used with cement-based mortar. However, the mortar will lose its viscosity if the mixture has high alkaline content.


The water-retention capacity of carboxymethyl cellulose is significantly lower as compared to methyl cellulose. It also has a stronger retarding effect on gypsum-based mortar and works to reduce the mortar’s strength. However, the affordable price of CMC makes it more convenient and cost-efficient to use as compared to other cellulose-based construction compounds.

What are the Uses of Carboxymethyl Cellulose?

Carboxymethyl cellulose as a viscosity modifier or thickener is used in the food industry when hydrolyzed at the enzyme level, besides being used as a stabilizing emulsion. CMC is a common ingredient of several non-food products, such as textile sizing, water-based paints, laxatives, paper products, toothpaste, diet pills, detergents, and reusable heat packs.

As it has high viscosity and is non-toxic, CMC is widely used as a hypoallergenic and a major source of fiber. CMC is also very useful in gluten-free and reduced-fat food items. Besides this, CMC is also utilized as a soil suspension polymer that is useful to deposit onto cotton and other cellulose-laced fabrics in detergent powders. It also acts as a lubricant to cover artificial tears.

Let’s find out some of the varied uses of carboxymethyl cellulose –

Thickening Agent

Carboxymethyl cellulose is incredibly useful as a thickener. It is very useful as a drilling mud ingredient during obtaining oil from underground deposits. It works as a viscosity modifier and water retention agent.

Besides this, Na CMC (Sodium Carboxymethyl Cellulose) has been used in rabbits as a negative control agent to treat alopecia. Apart from this, knitted fabric made of CMC, such as cotton or viscose rayon, can be transformed into CMC and used in various medicinal applications, such as –

  • Device to stop nose bleeding (epistaxis)
  • Post-surgical fabric dressing on the nose, ear, and throat
  • Gel to insert into sinus cavity after surgery

Insoluble micro granular CMC is also used as a cation-exchange resin for purification of proteins in ion-exchange chromatography. The micro granular cellulose retains its solubility properties as the derivatization level is remarkably low. At the same time, it adds sufficient negatively charged carboxylate groups to bind them into positively charged proteins.

Ice Packs

CMC is widely used in creating long-lasting ice packs. It forms a eutectic mixture which results in a low freezing point, that inherently makes the cooling capacity of CMC significantly more than ice.

Aqueous Solutions

Aqueous solutions with CMC are commonly used for dispersing carbon nanotubes. These nanotubes are covered with the long CMC molecules and disperse in the water. CMC is used as an adhesive or fixative, in water conservation and restoration processes.


CMC is also utilized to obtain cold stability or tartrate in wine. Wine is normally chilled by using electrical appliances in warm climates, which generates significant utility bills. However, using CMC can help avoid raising the electricity bills as it is a more stable option as compared to metatartaric acid. Besides, CMC is also highly efficient in preventing precipitation of tartrate.

Based on research, we know that the presence of CMC also affects KHT crystals by not only changing their morphology, but also slowing down their growth. It changes the KHT crystals into flattened shapes by eliminating 2 of the 7 faces. The CMC molecules also interact with the crystals’ electropositive surface while containing the potassium ions at the surface.

As the CMC molecule and bitartrate ions compete to bind with the KHT crystals it causes the crystal to grow slower and change its shape remarkably.

Veterinary Medicine

CMC finds application as veterinary medicine in large animals. For instance, it helps during abdominal surgeries and to prevent bowel adhesion development, in horses and cows.

Electrode Binder

Carboxymethyl cellulose is also used as an electrode binder in Lithium-Ion and similarly advanced batteries, especially those with graphite anodes.

As CMC is soluble in water it is utilized as a less toxic and more affordable processing agent, as compared to binders that are non-soluble in water. For instance, the conventional PVDF (polyvinylidene fluoride) requires the noticeable toxic NMP (n-methyl pyrrolidone) for processing.

However, electrodes that need greater flexibility, CMC is mostly used in combination with SBR (styrene-butadiene rubber).


CMC is most widely used in the detergent industry. Mostly, the industrial grade CMC is a crucial ingredient in manufacturing soaps and detergents. The CMC acts as an inhibitor and prevents the staining substance from getting re-deposited on the fabric once the detergent removes it during the laundry process.


CMC also has wide uses in the adhesive industry. It is a common ingredient in manufacturing various conventional and special glues and adhesives. It is also highly useful in the leather processing industry. Apart from this, CMC is combined with starch and phenol-formaldehyde to join two wooden surfaces together.


Carboxymethyl cellulose is widely used in the construction industry today. It is primarily used as a hydrophilic agent and a stabilizer in cement and building materials, such as concrete, mortar, putty, paint, etc.

Carboxymethyl cellulose fibers also enhance the dispersion of sand particles in the cement which improves the cement’s bonding strength. Besides this, CMC is also used as a glue in flooring and tiling processes.

It is highly recommended to buy carboxymethyl cellulose products from renowned brands such as Sakshi Chem Sciences Pvt Ltd, to ensure the best results desired for any construction project.