Carboxymethyl Cellulose (CMC) or cellulose gum[1] 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. It is often used as its sodium salt, sodium carboxymethyl cellulose. It used to be marketed under the name Tylose, a registered trademark of SE Tylose.[2]
Preparation
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Carboxymethyl cellulose is synthesized by the alkali-catalyzed reaction of cellulose with chloroacetic acid.[3] The polar (organic acid) carboxyl groups render the cellulose soluble and chemically reactive.[4] Fabrics made of cellulose—e.g. cotton or viscose rayon—may also be converted into CMC.[5]
Following the initial reaction, the resultant mixture produces approximately 60% CMC and 40% salts (sodium chloride and sodium glycolate). This product, called technical CMC, is used in detergents.[citation needed] An additional purification process is used to remove salts to produce pure CMC, which is used for food and pharmaceutical applications.[citation needed] An intermediate "semi-purified" grade is also produced, typically used in paper applications such as the restoration of archival documents.[citation needed]
Structure and properties
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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.[citation needed]
Uses
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Introduction
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Carboxymethyl cellulose (CMC) is used in a large variety of applications ranging from food production to medical treatments.[6] It is commonly used as a viscosity modifier or thickener, and to stabilize emulsions in various products, both food and non-food. It 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.[7][8][9][verification needed]
Food science
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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.[8][7] CMC is also used extensively in gluten-free and reduced-fat food products.[10]
Marshmallows: CMC not only prevents dehydration and shrinkage of the product but also contributes to a more airy structure. When combined with gelatin, it can significantly increase the viscosity of the gelatin. A high molecular weight CMC (DS around 1.0) should be selected.
Ice cream: CMC has a lower viscosity at higher temperatures, and the viscosity increases upon cooling, which is conducive to the improvement of the expansion rate of the product and facilitates operation. It is advisable to use CMC with a viscosity of 250~260 mPa·s (DS around 0.6), and the reference dosage should be less than 0.4%.
Fruit juice beverages, soups, sauces, and instant soluble drinks: Due to CMC's good rheological properties (pseudoplasticity), it delivers a refreshing taste, and its excellent suspension stability ensures uniform flavor and texture throughout the product. For acidic fruit juices, a CMC with good uniformity in degree of substitution is required. If it is further blended with a certain proportion of other water-soluble gums (such as xanthan gum), the effect can be even better. A high viscosity CMC (DS0.6~0.8) should be selected.
Instant noodles: The addition of 0.1% CMC helps to control moisture content, reduce oil absorption, and can also enhance the glossiness of the noodles.
Dehydrated vegetables, tofu skin, and dried tofu sticks, and other dehydrated foods: They rehydrate well and easily, and have a good appearance. It is advisable to use high viscosity CMC (with a degree of substitution around 0.6).
Noodles, bread, and frozen foods: CMC can prevent starch retrogradation and dehydration, and control the viscosity of pastes. The effect is further improved when used in combination with konjac flour, xanthan gum, certain emulsifiers, and phosphates. A medium viscosity CMC (DS0.5 to 0.8) should be selected.
Orange juice, pulpy orange, coconut juice, and fruit tea: Because it provides excellent suspension and support, it is even better when combined with xanthan gum or agar. A medium viscosity CMC (DS around 0.6) should be selected.
Soy sauce: The addition of salt-tolerant CMC to adjust its viscosity can make the soy sauce have a delicate and smooth taste.
Vegetarian burgers: CMC is used to enhance the texture, stability, and shelf life of vegetarian burgers, making them more palatable and easier to handle during cooking and consumption. [11]
Detergent uses
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Detergent Grade Carboxymethyl Cellulose (CMC) is a cornerstone ingredient in modern cleaning products. CMC is used for its thickening and stabilizing properties, enhancing the texture and efficiency of detergents. It plays an important role in improving soil suspension and preventing redeposition, making it essential for high-performance laundry and dishwashing detergents. With a tailored viscosity range, CMC ensures detergents maintain optimal consistency, crucial for both liquid and powder formulas. Its compatibility with diverse detergent ingredients, including surfactants and builders, allows for versatile applications.
Laundry Detergents: Incorporate 5% CMC to improve soil suspension and fabric care. Blend with surfactants, builders, and fragrance. This formulation ensures efficient cleaning and fabric protection, making laundry detergents more effective.
Dishwashing Liquids: Use 3% CMC for enhanced grease removal and suds stability. Combine with cleaning agents and scents. This mix results in a powerful dishwashing liquid that cuts through grease and leaves dishes spotless.
Powdered Detergents: Add 4% CMC to prevent caking and ensure smooth texture. Mix with cleaning agents, brighteners, and fragrance. This formulation keeps powdered detergents free-flowing and effective.
Hand Washes: Blend 2% CMC for a luxurious, moisturizing feel. Include cleansing agents and essential oils. This composition creates hand washes that clean effectively while being gentle on the skin.
Surface Cleaners: Incorporate 1.5% CMC to enhance cleaning power and leave a streak-free finish. Mix with disinfectants and fragrances. This formula is ideal for multi-surface cleaners that effectively clean and freshen surfaces.
Car Wash Solutions: Use 2% CMC to remove tough dirt and grime. Combine with cleaning agents and wax for shine. This formulation results in a car wash solution that cleans effectively without damaging the vehicle’s finish.
Fabric Softeners: Add 3% CMC to fabric softeners for improved texture and fabric conditioning. Blend with softening agents and scents. This formula makes fabrics feel soft and smell fresh.
Toilet Bowl Cleaners: Incorporate 2% CMC for enhanced cling to bowl surfaces. Mix with disinfectants and cleaning agents. This formula ensures a thorough clean and lasting freshness in toilet bowl cleaners.
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Textile uses
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Textile Grade Carboxymethyl Cellulose (CMC) is an essential component in the textile industry, widely used for its diverse applications. Primarily, it’s employed as a thickening agent in textile printing, constituting about 2-3% of printing pastes, to achieve sharp, clear designs. In dyeing processes, CMC, at a concentration of 1-2%, aids in uniform dye dispersion and fixation, ensuring vibrant and consistent colors. It’s also used in fabric finishing, at about 0.5-1%, to enhance fabric hand feel and texture. Additionally, CMC serves as a binding agent in non-woven fabrics, contributing to the strength and stability of the material. In sizing applications, about 1-3% of CMC is used to protect yarns during weaving, reducing breakages. The product’s role in fabric softening and conditioning is pivotal, improving the overall quality and wearability of textiles.
Textile Printing: Mix 3% CMC to create thickened printing pastes, ensuring precise and vibrant prints on fabrics. Blend with dyes and water to achieve desired consistency. This application results in sharp, clear textile designs that are visually appealing.
Fabric Dyeing: Use 2% CMC for even dye distribution and improved color fixation in fabric dyeing. Combine with fabric dyes and water, ensuring uniform application. This leads to consistently colored fabrics with long-lasting hues.
Fabric Finishing: Incorporate 1% CMC in finishing solutions to enhance fabric feel and appearance. Mix with finishing agents and apply to textiles. This application gives fabrics a soft, luxurious texture and improves wear resistance.
Yarn Sizing: Apply 3% CMC in sizing mixtures to protect yarn during weaving. Blend with starches and size mixtures, enhancing yarn strength and reducing breakages in the loom. This ensures smoother weaving and higher-quality textiles.
Non-Woven Fabric Production: Use 2% CMC as a binder in non-woven fabrics for increased strength and stability. Combine with fibrous materials, creating durable and cohesive non-woven textiles used in various applications.
Fabric Softening: Add 1.5% CMC to softening solutions for a softer fabric hand feel. Mix with softeners and apply to textiles, resulting in comfortable and pleasant-to-touch fabrics, ideal for clothing and home textiles.
Textile Coatings: Incorporate 2.5% CMC in coating formulations to improve fabric coating uniformity. Blend with coating materials, enhancing the protective properties of coated fabrics used in specialty applications.
Printing Thickener Replacement: Use CMC as an eco-friendly alternative to synthetic thickeners in printing pastes. Mix 3% CMC to achieve the desired viscosity, providing a sustainable and effective solution for textile printing.[13]
Cosmetics uses
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Cosmetics Grade Carboxymethyl Cellulose (CMC) is a versatile ingredient used in over 50% of cosmetic products for its exceptional properties. As a thickening agent, it’s crucial in formulations where viscosity needs to be precisely controlled, commonly found in 30-40% of skincare products. In hair care, about 25% of shampoos and conditioners utilize CMC for its conditioning and detangling effects. It’s also a staple in makeup, contributing to the texture and stability of around 20% of foundations and mascaras. In toothpaste, making up approximately 15% of the market, CMC enhances texture and consistency. Its moisture retention properties are vital in 35% of moisturizers and lotions, ensuring skin hydration. Moreover, CMC serves as a film-forming agent in approximately 10% of sunscreens, improving application and wear. These diverse applications underscore CMC’s critical role in enhancing the quality and performance of cosmetic products. Cleansing Lotion: Formulate with 1.5% CMC (FH9), 5% Beta-Cyclodextrin Hydrate, 15% Liquid Paraffin, and 5% Glycerin. Add suitable preservatives and fragrances. Mix with distilled water to make up to 100%. This emulsion serves as an excellent and stable cosmetic product.
Almond Cream: Use 1.3% CMC (FH9), 9.9% Almond Oil, 0.2% Bitter Almond Oil, 0.8% Geranium Oil, and 90% Ethanol. Include appropriate amounts of preservatives and fragrances. Mix well, then dilute with 100% distilled water. This almond cream offers excellent skin protection and anti-wrinkle benefits.
Lipstick: CMC aids in pigment suspension and dispersion, binding other ingredients for even distribution. For more information, contact Carboxymethyl Cellulose suppliers. Dosage: 0.5%-1.0%, using grade FH9.
Royal Jelly Face Mask: Royal Jelly, a precious natural nourisher, stimulates gland activity and disease resistance, offering special skin protection. Adding CMC to the face mask ensures uniform distribution of ingredients and enhances skin hydration. It also has excellent film-forming properties. Formula: 2% CMC (FH9), 1% Sodium Alginate, 5% Polyethylene Glycol, 1% Carbomer 940, 1.5% Polyoxyethylene Lauryl Ether, 10% Ethanol, 0.5% Triethanolamine, 5% Glycerin, 0.5% Royal Jelly, and 73.5% Refined Water, with a suitable amount of preservative.
Shampoo: CMC combined with Fatty Acid Ethanolamine or 2,2'-Iminodiethanol forms a thin film around hair, providing a sleek effect. Typical Formula: 2.5% CMC (FH9), 10% Propylene Glycol (plasticizer), 44.6% Water, Triethanolamine, 20% Sodium Lauryl Sulfate (cleansing agent), Sorbitol, 3% Polyoxethylene (adjusting agent), 2% Sodium Stearate (brightener), 0.8% Dye, Fragrances, and a suitable amount of preservative.
Anti-Aging Serum: A formula comprising 0.7% CMC (FH9) for a smooth, gel-like texture. It includes 10% Hyaluronic Acid for deep hydration, 2% Vitamin C for skin brightening, and 5% Collagen for elasticity. The base is a mixture of 70% water and 10% Glycerin, enhanced with natural antioxidants and preservatives.
Sunscreen Lotion: Formulated with 2% CMC (FH9) for consistency and stability. It contains 10% Zinc Oxide and 5% Titanium Dioxide for broad-spectrum UV protection. Additional ingredients include 5% Aloe Vera for soothing and 3% Vitamin E for skin repair. The base is 70% water, with added emollients and preservatives.
Hand Cream: This cream uses 1.5% CMC (FH9) for a rich texture. Key ingredients include 5% Shea Butter for moisturizing, 2% Glycerin for hydration, and 0.5% Allantoin for skin repair. The formula is enhanced with 80% water, essential oils for fragrance, and preservatives to maintain shelf life.
Hair Styling Gel: A formulation with 1.2% CMC (FH9) for strong hold and flexibility. It includes 5% Vegetable Glycerin for moisture, 2% Pro-Vitamin B5 for hair strength, and 0.5% Argan Oil for shine. The base consists of 85% water, along with natural fragrances and preservatives for a lasting effect.[14]
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. It is more stable than metatartaric acid and is very effective in inhibiting tartrate precipitation. It is reported that KHT crystals, in presence of CMC, grow slower and change their morphology.[15][non-primary source needed][better source needed] 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.[16][full citation needed]
Specific culinary uses
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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.[17] 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. 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. It can also help to reduce the amount of egg yolk or fat used in making the biscuits. Use of CMC in candy preparation ensures smooth dispersion in flavor oils, and improves texture and quality. CMC is used in chewing gums, margarines and peanut butter as an emulsifier.[18]
Medical applications
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CMC is also used in numerous medical applications.[19][20][21][22]
Some examples include:
citation needed
]citation needed
]citation needed
]In ophthalmology, CMC is used as a lubricating agent in artificial tears solutions for the treatment of dry eyes.[23]
In veterinary medicine, CMC is used in abdominal surgeries in large animals, particularly horses, to prevent the formation of bowel adhesions.[citation needed]
Research applications
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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.[24] Its 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.[25] Insoluble CMC offers physical properties similar to insoluble cellulose, while the negatively charged carboxylate groups allow it to bind to positively charged proteins.[26] Insoluble CMC can also be chemically cross-linked to enhance the mechanical strength of the material.[27]
Moreover, 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.[citation needed] CMC is desirable because the catalysis product (glucose) is easily measured using a reducing sugar assay, such as 3,5-dinitrosalicylic acid.[citation needed] Using CMC in enzyme assays is especially important in screening for cellulase enzymes that are needed for more efficient cellulosic ethanol conversion.[citation needed] CMC was misused in early work with cellulase enzymes, as many had associated whole cellulase activity with CMC hydrolysis.[according to whom?] As the mechanism of cellulose depolymerization became better understood, it became clear that exo-cellulases are dominant in the degradation of crystalline (e.g. Avicel) and not soluble (e.g. CMC) cellulose.[citation needed]
Other uses
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In laundry detergents, it 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.[citation needed] 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.[citation needed]
CMC is sometimes used as an electrode binder in advanced battery applications (i.e. lithium ion batteries), especially with graphite anodes.[28] 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.[citation needed] CMC is often used in conjunction with styrene-butadiene rubber (SBR) for electrodes requiring extra flexibility, e.g. for use with silicon-containing anodes.[29]
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.[30]
Aqueous solutions of 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.[citation needed]
In conservation-restoration, it is used as an adhesive or fixative (commercial name Walocel, Klucel).[citation needed]
Adverse reactions
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Effects on inflammation, microbiota-related metabolic syndrome, and colitis are a subject of research.[31] Carboxymethyl cellulose is suggested as a possible cause of inflammation of the gut, through alteration of the human gastrointestinal microbiota, and has been suggested as a triggering factor in inflammatory bowel diseases such as ulcerative colitis and Crohn's disease.[32][non-primary source needed]
While thought to be uncommon, case reports of severe reactions to carboxymethyl cellulose exist.[33] Skin testing is believed to be a useful diagnostic tool for this purpose.[34] Carboxymethyl cellulose was the active ingredient in an eye drop brand Ezricare Artificial Tears which was recalled due to potential bacterial contamination.[35]
See also
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References
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