Ethyl ether of cellulose

The ethyl ether of cellulose contains no less than 45% and not more them 50% ethoxy groups. It is available as a free-flowing stable white powder, insoluble in water, glycerol, and other hydrophilic solvents, but soluble in organic solvents such as ethanol, ethylacetate, and chloroform. This cellulose derivative is mainly used as a tablet binder. 

PROP Ethyl ether of cellulose. White to light tan powder. Sol in some org solvs insol in water, glycerin, and propylene glycol. 

Desmans AJ, Went RF (1993) Hydroxyalkyl and ethyl ethers of cellulose. In Reference 113, p505... 

Ethylcellulose is an ethyl ether of cellulose containing 44-51% of ethoxyl groups. It is insoluble in water but soluble in chloroform and in alcohol. It is possible to form water-soluble grades with a lower degree of substitution. 

Precautions Harmless when used for intended purpose. Synonyms cas 9004-57-3 ethyl ether of cellulose Ethyl Cinnamate... 

Synonyms Carbor ethylcellulose Carbor ethylcellulose, sodium salt Carboxymethyl ether cellulose sodium salt Cannellose sodium Cellulose carboxymethyl ether Cellulose carbor methyl ether sodium salt Cellulose glycolic acid sodium salt Cellulose gum (INCI) Cellulose, polyanionic Cellulose sodium glycolate CMC CMC sodium salt NaCMC SCMC Sodium carboxymethylcellulose Sodium cellulose glycolate Sodium CMC Sodium CMSodium salt of the polycarbot ethyl ether of cellulose Fornujia RnOCHjCOONa... 

Definition Ethyl ether of cellulose Properties Wh. to It. tan powd. sol. in most org. liqs., alcohol, aromatic soivs. insol. in water, glycerol, propylene glycol dens. 1.07-1.18 ref. index 1.47... 

Ethyl cellulose (1936) (EC) n. An ethyl ether of cellulose formed by reacting cellulose steeped in alkali with ethyl chloride it is a... 

Desmarais AJ, Wint RF. HydroxyaUcyl and ethyl ethers of cellulose. In Whistler RL, Be-Miller JN, eds. Industrial Gums Polysaccharides and Their Derivatives. San Diego Academic Press, 1993 505-535. 

Methyl and ethyl ethers of cellulose with a degree of substitution (D.S.) of 0.1 to 0.35 are used as emulsifying agents and paper sizes. Hydroxy-ethylcellulose (D.S., 0.5) is also used as a size. Highly substituted ethyl-celluloses (D.S., 2.2 to 2.6) are of great importance in the plastics, film, and lacquer industries. Carboxymethylcellulose (D.S., 0.5 to 0.75) is used as a thickener in foods, and the sodium salt is added to washing powders in which its action in laundering is to prevent redeposition of soil in the fabric. 

Ethyl cellulose, an ethyl ether of cellulose, is available in a variety of grades, which differ in their viscosity. Low-viscosity grades are used as binders in concentrations of 2-10% in ethanol. Ethyl cellulose produces softer granules, which compress into tablets that easily disintegrate. However, the dissolution of the active ingredient from these tablets may be slower because ethyl cellulose is insoluble in water. Ethyl cellulose may be used in a dry form or in an ethanolic solution for wet granulation. Ethyl cellulose is a good nonaqueous binder for water sensitive formulations. 

Ethylcellulose is an ethyl ether of cellulose, prepared by ethylation of the alkali cellulose, whose most important property is to be insoluble in water. Different ethylcelluloses are commercially available varying both the ethoxyl content (45.0-49.5%) (Ethocel , by Dow Chemical Company) and viscosity values (10-100 cP). As a general rule, viscosity increases as the molecular weight (MW) of polymer increases. The lower viscosity grades of this polymer are more compressible and compactible, leading to harder tablets and, consequently, to lower drug dissolution rates [14-16], This increase in com-pactibility has been explained based on the fact that the polymers with lower MW show a less ordered structure [14]. 

The methyl and ethyl ethers of cellulose have properties that are similar to those of the ester derivatives, and they have been used for related applications. Ethyl cellulose is injected-molded into parts with good low-temperature toughness and used as an additive in coatings and adhesives to improve flexibility. The methyl derivative is used as a thickener and emulsifier for paints, adhesives, food, and pharmaceutical products. 

Etherification. Carbohydrates are involved in ether formation, both intramoleculady and intermoleculady (1,13). The cycHc ether, 1,4-sorbitan, an 1,4-anhydroalditol, has already been mentioned. 3,6-Anhydro-a-D-galactopyranosyl units are principal monomer units of the carrageenans. Methyl, ethyl, carboxymethyl, hydroxyethyl, and hydroxypropyl ethers of cellulose (qv) are all commercial materials. The principal starch ethers are the hydroxyethyl and hydroxypropylethers (see Cellulose ethers Starch). 

Xanthx Acid.—Another solvent of cellulose is xanthlc acid, also called xanthonic or xanthogenic acid. Xanthic acid is the ethyl ether of -di-thio-carbonic acid. Its formula is HS-CS-OC2H5. When heated with water to 500° under pressure cellulose is dissolved and undergoes decomposition. 

Viscose Silk.—III. From Cellulose Xanthate. We have referred to the solvent action of xanthic acid, which is the ethyl ether of di-thio-carbonic acid, viz., HS-CS-OC2H5. When sodium cellulose is dissolved in xanthic acid the cellulose is in the form of sodium cellulose xanthate. A solution properly prepared by treating cellulose with sodimn hydroxide and carbon di-sulphide in the presence of benzene or carbon tetra-chloride, in which polymerization of the cellulose compound is effected, is decomposed by forcing capillary streams of the solution into a solution of ammonium sulphate. The cellulose is thus obtained as in the other processes in the form of fine filaments of a hydrated cellulose possessing silk-like properties. Artificial silk of this type is known as viscose silk and is made in large quantities. In 1914 about 20,000,000 pounds of artificial silk were made, of which about 3,000,000 pounds were made in the United States. Most of this product was viscose silk. 

Methyl, ethyl, and benzyl ethers of cellulose are important in the production of textiles, films, and various plastic objects. 

Ethylhydroxyethylcellulose is an ether of cellulose with both ethyl and hydroxyethyl substituents attached via ether linkages to the anhydroglucose rings. It swells in water to form a clear viscous colloidal solution. Preparation of solutions of cellulose derivatives requires hydration of the macromolecules, the rate of which is a function of both temperature and pH, as shown in the example in Fig. 8.f8. 

Ethoxypropyl cellulose [59], an ethyl ether of HPC forms excellent thermotropic and lyotropic mesophases, the lyotropic ones with acetonitrile, dioxane, and methanol. Both thermotropic and lyotropic systems exhibit cholesteric phases with a right-handed helicoidal supermolecular structure,... 

Ethyl lactate is a colorless and olmost odorless liquid, which, upon evaporotion, will sometimes develop a disagreeable odor. This is owing to the iactides, or inner anhydrides, contained in the lactic acid mode by fermentation. It is miscible with water, alcohols, ketones, esters, hydrocarbons and oils. Ethyl lactate will dissolve cellulose acetate ond nitrate ond many of the ethers of Cellulose. It is also a solvent for basic dyes, alkyd resins, kauri, manila, pontionac, rosin, shellac and vinyl resins. Ethyl lactate has high solvent power and equally high tolerance far nonsolvents and diluents. These exceptional properties are accounted for by the existence of both an alcohol and an ester group in its molecule. 

Cellulosic membranes are developed as a novel dmg delivery system, which is expressed to use on the skin and used as a mucus membrane of stomach, ear, nose, eye, rectum, and vagina. The goal excipients of these preparations are adhesive and film-former polymers. Modified cellulose, especially cellulose ethers, are extensively applied in bio-adhesives such as nasal, vaginal, ocular, buccal, and transdermal inventions only or by blend with additional polymers. Further newly applied ethers of cellulose in bio-adhesives contain anionic ether derivatives such as sodium carboxy-methyl cellulose (NaCMC) and non-ionic cellulose ethers such as hydoxypropyl cellulose (HPC), carboxymethyl cellulose (CMC), hydroxyethyl cellulose, ethyl cellulose (EC), hydroxylpropylmethyl cellulose (HPMC), or methyl cellulose (MC). Capability of polymer to absorb water from mucus and pH of objective area are main features defining the adhesive power of polymers. One benefit of cellulose ethers, such as HPC and NaCMC, is smaller dependence of adhesion period and their adhesion strength to pH of medium than thiolated bio-adhesive polymers and polyacrylate... 

Numerous ethers of cellulose, starch, and bacterial dextran are of established or potential industrial importance. (See also Chapter XII.) Treatment of the polysaccharides with alkali and methyl chloride, ethyl chloride, benzyl chloride, ethylene oxide (or ethylene chlorohydrin), sodium chloro-acetate, and allyl bromide gives, respectively, the methyl, ethyl, benzyl, hydroxy ethyl, carboxy methyl, and allyl ethers. The cellulose derivatives... 

Anhydro-Alditols. - 2-And/or 3-methyl or ethyl ethers of methyl f-D-glucopyranoside have been used to prepare a series of 2- and/or 3- and/or 6-methyl and/or ethyl ethers of 1,5-anhydro-D-glpcitol, which can also be reductive cleavage products of partially methylated or ethylated celluloses. 

Ethyl Cellulose n (1936) (EC) An ethyl ether of ceUulose formed by reacting ceUulose steeped in alkali with ethyl chloride it is a white granular thermoplastic resin. Since the repeating units are etheric, it is chemicaUy different from other ceUulosics, which are esters, and is therefore not compatible with them. EC resin can be injection molded, extruded, cast into film, or used as a coating material. It has the lowest density of aU ceUulosic plastics, good toughness and impact resistance, and is dimension-aUy stable over a wide temperature range. Syn Carbitol. 

A number of compounds of this type are in use and they consist of methyl (and in some cases ethyl or hydroxypropyl)ethers of cellulose they are characterised by their alkoxyl content. A general method for the determination of methoxyl groups is as follows ... 

By use of a modification of the well-known Williamson synthesis it is possible to prepare a number of cellulose ethers. Of these materials ethyl cellulose has found a small limited applieation as a moulding material and somewhat greater use for surfaee eoatings. The now obsolete benzyl cellulose was used prior to World War II as a moulding material whilst methyl eellulose, hyroxyethyl eellulose and sodium earboxymethyl eellulose are useful water-soluble polymers. 

Nitro-filter cloths are composed of cellulose nitrate, which is an ester of cellulose. Any chemical compound that will saponify the ester will destroy the cloth. Caustic soda or potash in strengths of 2% at 70° C or over alkali sulfides, polysulfides and sulfohydrates or mixtures of ethyl alcohol and ether, ethyl, amyl and butyl acetates, pyridine, ferrous sulfates, and other reducing agents are detrimental to the cloth. 

Group of plastics composed of cellulose compounds, for example esters (e.g., cellulose acetate) and ethers (e.g., ethyl cellulose). 

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