CAS number：9004-32-4
molecular formula：C6H7O2(OH)2CH2COONa
molecular weight：0
EINECS number：618-378-6

English synonyms

Aquacide I, Calbiochem;Aquacide II, Calbiochem;Carboxyl Methyl Cellulose sodium;Cellex;Cellulose carboxymethyl ether, sodium;cellulose gum;SODIUM CARBOXY METHYL CELLULOSE (CMC);SCMC(SODIUM CARBOXY METHYL CELULLOSE

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Carbohydrates; fine chemicals; biochemical reagents; other raw materials for scientific research; pharmaceutical raw materials; inorganic salts; chemical additives; oilfield chemicals; petroleum drilling chemicals; food additives; thickeners; drilling chemicals; papermaking process Chemicals; Paper Chemicals; Thickeners and Gelling Agents; Professional Reagents; Organic Chemistry; Life Sciences; Excipients; Pharmaceutical Excipients; Biological Sciences; Chemical Reagents; Chemical Products - Organic Chemicals; Biochemical Reagents - Separation Materials and  Consumables;MudDrillingChemicals;Foodadditives;CellulChemicalbookose;MaterialsScience;NaturalPolymers;PolymerScience;Polymers;thickener;Cellulose; organic chemical raw materials; raw materials; other raw materials; biochemical reagents - separation materials and consumables; pharmaceutical raw materials; pharmaceuticals, pesticides and dye intermediates; chemical materials; chemical raw materials; organic chemical raw materials; raw materials; fine chemical raw materials ;All products;Medical raw materials;Bulk goods;Food thickeners;Chemical reagents;Feed additives;Environmental microorganisms-commonly used medium

Introduction

Sodium carboxymethylcellulose (CMC) is a carboxymethylated derivative of cellulose, also known as cellulose gum, which is an anionic fiber Chemicalbook cellulose ether, and is the most important ionic cellulose gum. It is usually an anionic polymer compound obtained by reacting natural cellulose with caustic alkali and monochloroacetic acid. The molecular weight of the compound varies from several thousand to one million.

CMC is white or milky white fibrous powder or granules with a density of 0.5-0.7 g/cm3, almost odorless, tasteless and hygroscopic. It is easy to disperse in water to form a transparent colloidal solution, and is insoluble in organic solvents such as ethanol. The pH of the 1% aqueous solution is 6.5-8.5. When the pH is >10 or <5, the viscosity of the glue decreases significantly, and the performance is the best at pH=7. It is thermally stable, the viscosity rises rapidly below 20 Chemicalbook ℃, and changes slowly at 45 ℃, and long-time heating above 80 ℃ can make its colloid denatured and its viscosity and performance drop significantly. It is easily soluble in water, and the solution is transparent; it is very stable in alkaline solution, and is easily hydrolyzed in the presence of acid. When the pH value is 2-3, it will precipitate, and it will also react with polyvalent metal salts. Solid CMC is stable to light and room temperature, and can be stored for a long time in a dry environment.

Chemical properties

The properties of sodium carboxymethyl cellulose are as follows

●   Hygroscopic properties, the degree of hygroscopicity is related to the atmospheric temperature and relative humidity. When it reaches equilibrium, it will no longer absorb moisture.

●   CMC aqueous solution has excellent adhesion, thickening, emulsification, suspension, film-forming, protective colloid, moisture retention, anti-enzymatic hydrolysis and metabolic inert properties.

●  When the CMC aqueous solution meets tin, silver, aluminum lead, iron, copper and some heavy metals, a precipitation reaction will occur; when the CMC aqueous solution coexists with calcium, magnesium, and salt, precipitation will not occur, but it will reduce the CMC aqueous solution. viscosity. When the CMC aqueous solution encounters acid, the acid CMC precipitate will be precipitated. But acid-resistant CMC has certain resistance to acid solution.

●  Solubility: CMC aqueous solution and water-soluble animal glue, glycerol glycol, sorbitol, arabic

●  White or light yellow fibrous powder, odorless and tasteless. It is easy to disperse in water to become a transparent colloid, insoluble in organic solvents such as ethanol, acetone and ether. It is hygroscopic, and the pH value of 1% aqueous solution is 6.5 to 8.0. Thermally unstable Chemicalbook, the viscosity decreases when the temperature increases, the browning temperature is 226-228 °C, and the carbonization temperature is 252-253 °C. Oral LD5027g/kg of mice, ADI does not make special regulations (FAO/WHO, 1994).

Use

●  As an emulsion stabilizer and thickener. my country stipulates that it can be used for instant noodles, the maximum usage is 5g/kg; the maximum usage in beverages (excluding solid beverages) is 1.2g/kg; in biscuits, puffed foods, popsicles, ice creams, cakes and jelly, use in moderation according to production needs .

●  Thickener, Stabilizer; Texture Improver; Gelling Agent; Non-nutritive Leavening Agent; Moisture Movement Control Agent; Because of its viscosity, stability, protective colloid, and film forming properties, it is used in ice cream to improve water retention and tissue structure (0.3% to 0.5%). But it needs to be used in combination with sodium alginate, etc. It is used for quick-cooking noodles to make the product uniform, improve the structure, easy to control the moisture, and easy to operate. Adding to jam, cream, peanut butter, etc. can improve spreadability. The dosage of jam and sauce is 0.5% to 1%. Adding 0.1% to wheat for bread and cakes can prevent water evaporation and aging. It is still used as a solid agent for powder oils, spices, etc., and the dosage is 20% to 60% (CMC aqueous solution is mixed with oil, spices, etc., fully emulsified, dried, and crushed). Foam stabilizer for beer. Fruits, vegetables, eggs, etc. are coated and dried with 2% to 3% CMC solution containing parabens to maintain flavor and prevent mildew. After absorbing water, it has strong swelling and indigestion, and can be used as a diet food such as biscuits.

●  Widely used as thickener, suspending agent, binder, protective colloid, etc.

●  For oil drilling, textile printing and dyeing

●  Used in oil and gas drilling mud stabilizers, textile slurries, paper strengthening agents, adhesives, etc.

●  For combined washing, cigarettes, construction, daily chemicals

●  For textile sizing, drilling, etc.

●  Used as a chemicalbook agent for water-based drilling fluid filtration reduction and has a certain viscosity-increasing effect.

●  It can be used as a reinforcing agent in the pulp, and also used for surface sizing, and as a viscosity modifier when coating processed paper.

●  The largest use of CMC is to formulate soaps and synthetic detergents. About 1% of CMC is added to heavy-duty cleaners to prevent the washed out dirt from re-precipitating on the fabric. Secondly, it is used as a suspension stabilizer for drilling mud in the petroleum industry. As an additive in the paper industry, it can improve the longitudinal strength and smoothness of the paper. As a coating, it can improve the printing adaptability of the paper. In the food industry, it is used as a thickener, Emulsion stabilizer and ice crystal inhibitor for ice cream; used as a thickener for sizing and printing and dyeing paste in the textile industry; in the pharmaceutical industry, it can be used as an emulsion stabilizer for injection, a binder for tablets and a film-forming agent; It is used as a thickener in the production of cosmetics and ceramics. The toxicity test of CMC showed that oral and skin contact had no physiological activity at all, and no toxicity was found even at a dose of 10 g/kg orally in mice. The special committees of the Food and Agriculture Organization of the United Nations and the World Health Organization have also confirmed the safety of this product, and stipulated that the allowable daily intake (ADI) of humans is 0-30mg/kg.

●  Polyanionic cellulose (PAC) for short is a water-soluble cellulose ether derivative obtained by chemical modification of natural cellulose. It is an important water-soluble cellulose ether, and its sodium salt is usually used. Polyanionic cellulose has good thermal stability and salt resistance, and strong antibacterial properties. The mud fluid prepared by this product has good water loss reduction, inhibition and high temperature resistance. Widely used in oil drilling, especially salt water wells and offshore oil drilling. PAC-LV: Low viscosity polyanionic cellulose

Production method

●  The production method of carboxymethyl cellulose is to react cellulose with sodium hydroxide to form alkali cellulose, and then carry out carboxymethylation with monochloroacetic acid. The preparation method can be divided into a water-based method in which the reaction is carried out with water as a medium and a solvent method in which the reaction is carried out in a solvent such as isopropanol, ethanol, and acetone.

●  Add refined cotton, caustic soda, alcohol mixture and chloroacetic acid alcohol solution into the kneader together for alkalization and etherification. Then neutralize with hydrochloric acid, wash with alcohol, then dry and pulverize to obtain the product.

●  Immerse the degreased and bleached cotton thread in 35% concentrated lye solution for about 30min and take out. The liquid caustic soda can be recycled. The soaked cotton short thread is weighed on the flat press, and the lye liquid is pressed out under the pressure of 14MPa to obtain alkalized cotton. Put the alkali cotton into the etherification kettle, add 15 parts of alcohol, slowly add chloroacetic acid alcohol solution under stirring, finish at 30°C for 2 hours, and stir at 40°C for 3 hours after adding to obtain etherified cotton. Add 120 parts of alcohol (70%) in etherified cotton, stir for 0.5h, and add hydrochloric acid to adjust the pH to 7. Wash twice with alcohol, filter out the alcohol, blow dry at 80°C, and pulverize to obtain the finished product. Depending on the ratio of ingredients, products with low substitution degree (<0.4) and medium substitution degree (0.4-1.2) can be produced.

●  Treat cellulose with sodium hydroxide to form alkali cellulose, mix with Chemicalbook sodium monochloroacetate, and mature for several days (20～30℃) to obtain the product

●  Usually, refined cotton is used as raw material, reacted with sodium hydroxide to generate alkali cellulose, and then carboxymethylated with chloroacetic acid to obtain the finished product. (C6H9O4OH)n+nNaOH→(C6H9O4ONa)n[ClCH2COOH]→(C6H9O4OCH2COONa)n The domestically used processes include the traditional water-based method with water as the medium and the solvent method with organic solvent as the reaction medium. In the traditional water-based method, 18%-19% lye is sprayed into the kneader, and the refined cotton is alkalized at 30-35°C to form alkali cellulose, and then kneaded and etherified with solid sodium chloroacetate. The temperature in the first 1 to 2 hours is controlled below 35 °C; the temperature in the last 1 hour is controlled at 45 to 55 °C. After a period of aging (to make etherification complete), it is dried and pulverized to obtain the finished product. The cotton is refined by solvent method in the kneader, and the lye is sprayed into the kneader at a certain flow rate to fully expand the cellulose. At the same time, an appropriate amount of ethanol is added, and the alkalization temperature is controlled at 30-40°C for 15-25min. After the alkalization is complete, spray into the chloroacetic acid ethanol solution, and etherify it at 50～60℃ for 2h. Neutralize and wash with ethanolic hydrochloric acid solution to remove sodium chloride, de-alcoholize with centrifuge to remove water, and finally dry and pulverize to obtain finished product.

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