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Ethyl hydroxyethyl cellulose Prepared at the 49th JECFA (1997)superseding specifications prepared at the 29th JECFA (1985),published in FNP 34 (1986) SYNONYM INS No. 467 DEFINITION Ethyl Hydroxyethyl Cellulose is cellulose in which both ethyl and hydroxyethyl groups are attached to the anhydroglucose units by ether linkages. Ethyl hydroxyethyl cellulose is prepared from cellulose by treatment with alkali, ethylene oxide and ethyl chloride. The article of commerce may be specified further by the viscosity of its aqueous solutions. Chemical names Ethyl hydroxyethyl cellulose, 2-hydroxyethyl ether of ethyl cellulose C.A.S. number 9004-58-4 Chemical formula [C6H7O2 (OH)x (OC2H5)y [O(CH2CH2O)mH]z]n where n is the degree of polymerisationx + y + z = 3y = 0.7 - 1.5 (degree of ethyl substitution, DS)m + z = 0.5 - 2.5 (molar hydroxyethyl substitution, MS) Structural formula Possible structural formula for a repeating unit of an ethyl hydroxyethyl cellulose with a DS = 1.0 and a MS = 1.0 Formula weight Unsubstituted structural unit: 162.14Structural unit with DS = MS = 1.0: 234Structural unit with DS = 1.0; MS = 2.0: 278Structural unit with DS = 1.5; MS = 0.5: 226Macromolecules: from about 40,000 (n about 175)up to about 350,000 (n about 1,300) Assay Not less than 7% and not more than 19% of ethoxyl groups (-OC2H5), and not less than 10% and not more than 38% of oxyethylene groups (-OCH2CH2-), on the dried and salt-free basis. DESCRIPTION Hygroscopic white or slightly yellowish or greyish, odourless granules or fine powder. FUNCTIONAL USES Emulsifier, stabilizer, thickener CHARACTERISTICS IDENTIFICATION Solubility Swelling in water, producing a clear to opalescent, viscous, colloidal solution; insoluble in boiling water and ethanol. Foam formation Vigorously shake a 0.1% solution of the sample. A layer of foam appears. This test permits the distinction of cellulose ethers from sodium carboxymethyl cellulose, alginates, and