Ethyl hydroxyethyl cellulose EHEC

Pereswetoff-Morath, L., Bjurstrom, S., Khan, R., Dahlin, M., and Edman, P. (1995), Toxicological aspects of the use of dextran microspheres and thermogelling ethyl(hydroxyethyl) cellulose (EHEC) as nasal drug delivery systems, Int. J. Pharm., 128, 9-21. 

The two major commercial organosoluble cellulose ethers, ethyl-cellulose and ethyl(hydroxyethyl)cellulose (EHEC), are filmforming polymers distinguished by unusual properties and versatility (22). They contribute to the basic film properties of special types of inks, coatings, and adhesives. Their special utility results from the following performance properties (23) ... 

The ability of surfactant binding is enhanced through the hydrophobic interaction between polymer hydrophobes and surfactant hydrophobes. Typical model polymers such as hydrophobically ethoxylated urethane (HEUR), ethyl hydroxyethyl cellulose (EHEC), and hydroxypropyl methyl cellulose (HPMC) have been the focus of study. 

There is a lot of literature so far on the study of hydro-phobic interaction of ethyl(hydroxyethyl)cellulose (EHEC) with various ionic surfactants in water. The techniques used in these studies are of electromotive force of N-tetradecylpyridinium bromide [1], of thermal gelation with sodium dodecylsulfate (SDS) [2], of Fourier transform NMR in the presence of dodecyltrimethylammonium bromide [3], of phase separation diagram with various kinds of anionic and cationic surfactants [4], and so on. These studies have focused on the complex formation between EHEC and these surfactants and on the concomitant phase separation of the polymer solution. 

Figure 13.1 The reaction scheme for production of ethyl hydroxyethyl cellulose (EHEC), which includes the reaction steps alkalization, ethoxylation and alkylation with ethyl chloride.

DHPTMC DHPTOEOS EHEC FICOLL or,w-dihydroxy poly(tetramethylene carbonate) or,w-dihydroxy poly(tri(oxyethylene)oxysuccinyl) ethyl hydroxyethyl cellulose ficoll... 

Synonyms Cellulose ethyl hydroxyethyl ether EHEC Hydroxyethyl eth-ylcellulose (INCI)... 

Aquaion 12M31P] Aquaion Cellulose Gum] Aquaion CMC-T] Aquaion CMC-Warp Size. See Carboxymethylcellulose sodium Aquaion CMHEC-37L. See Carboxymethyl hydroxyethyl cellulose Aquaion EHEC. See Ethyl hydroxyethyl cellulose... 

EH. See Ethylene glycol hexyl ether 2-EH. See 2-Ethylhexanol EHA. See Octyl acrylate 2-EH acid. See 2-Ethylhexoic acid EHEC. See Ethyl hydroxyethyl cellulose EHGE EHGE. See 2-Ethylhexyl glycidyl ether 2-EHMA. See 2-Ethylhexyl methacrylate D2EHPA. See Di (2-ethylhexyl) phosphate Ehrlich s reagent. Seep-Dimethylaminobenzaldehyde 2-EHS Base. See Ammonium 2-ethylhexyl sulfate... 

Mixed ethers of ethyl and hydroxyethyl cellulose (EHEC) with an ethyl DS 1 and a hydroxyethyl MS of 0.5-2 have properties like hydroxyethylated or hydroxypropylated MC and are used in similar applications. They have a gelling temperature of 65-70 C in aqueous solutions, Due to the high degree of - etherification, they are resistant to biodegradation. 

Figure 20.9. Cellulose can be modified by a relatively random substitution of hydroxyethyl and ethyl groups to give ethylhydroxyethyl cellulose (EHEC). In HM-EHEC, a low fraction of hydrophobic groups is inserted...

The manufacturing process for organo-soluble EHEC is similar to that for EC except that alkah cellulose reacts first with ethylene oxide to a low hydroxyethyl MS value of - 0.5 at a low temperature, - 50° C, followed by reaction of the ethyl chloride at a higher temperature. Additional by-products, which are removed during purification, include glycols and the reaction products of the glycols with ethyl chloride (glycol ethers). 

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