Alcohol ethoxysulfates applications

Alcohol ethoxysulfates have been used in field tests as foaming agents for nitrogen (394) and carbon dioxide (395). Application of alcohol ethoxysulfates is restricted due to its limited hydrolytic stability at low pH and elevated temperature (396). 

Both nonionic and anionic surfactants have been evaluated in this application (488,489) including internal olefin sulfonates (487, 490), linear alkylxylene sulfonates (490), petroleum sulfonates (491), alcohol ethoxysulfates (487,489,492). Ethoxylated alcohols have been added to some anionic surfactant formulations to improve interfacial properties (486). The use of water thickening polymers, either xanthan or polyacrylamide to reduce injected fluid mobility mobility has been proposed for both alkaline flooding (493) and surfactant enhanced alkaline flooding (492). Crosslinked polymers have been used to increase volumetric sweep efficiency of surfactant - polymer - alkaline agent formulations (493). 

Alkyl ether sulfates, also called alcohol ethoxysulfates, are prepared by addition of one to four oxyethylene groups to an alcohol which is then sulfated. Oxyethylation enhances water solubility and foaming over the analogous alcohol sulfate, giving a product useful in shampoos and in liquid and powdered detergents. The raw material for these products can be either natural fatty alcohols or primary or secondary synthetic alcohols, usually of C12-C18 chain length. The analogous alkylphenol ether sulfates are found in industrial applications. Ether sulfates are not as sensitive to water hardness as are other anionic surfactants. 

As was pointed out, refinement of ethoxysulfated alcohols is sometimes required to satisfy current standards for product quality, in particular 1,4-di-oxane content. Due to the particular characteristics and outstanding suitability of FAES for application in personal care detergent products, the commercially accepted content of 1,4-dioxane in FAES has been progressively reduced to meet the demand of higher safety margins for the end-users, without requiring any change in product formulation and choice of surfactant. 

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