Lauryl Ether Sulphate

Industrial ethyl alcohol may be added to lauryl ether sulphates (LES) in order to reduce the viscosity. Ethyl alcohol is produced on a large scale by the hydration of ethylene which is derived from petroleum cracking processes. 

Primary alcohol ethoxysulphates, lauryl ether sulphates (LES) quality, storage, handling and safety... 

SLES (sodium "lauryl" ether sulphate) should be stored at temperatures between 15-40 C since below 10°C the material is too thick to pump and above 40°C there is a danger of hydrolysis. 

Dahl B. (1989). "Processing, Storage and Handling of Lauryl Ether Sulphates". Paper presented at Practical Sulphonation Seminar, 18-20 April 1989, The Hague, The Netherlands. Center for Professional Advancement, P.O. Box H, East Brunswick, New Jersey 08816, USA. 

Liquid hand soaps are concentrated surfactant solutions that can be simply applied from a plastic squeeze bottle or a simple pump container. The formulation consists of a mixture of various surfactants such as alpha olefin sulphonates, lauryl sulphates or lauryl ether sulphates. Foam boosters such as cocoamides are added to the formulation. A moisturizing agent such as glycerine is also added. A polymer such as polyquaternium-7 is added to hold the moisturizers and to impart a good skin feel. More recently, some manufacturers used alkyl polyglucosides in their for-... 

Figure 6.27 Effect of increasing NaCl content on viscosity ( ) and rank order of odour intensity (0) of a solution of 2 % perfume W 100 in 12 % sodium lauryl ether sulphate and 2 % coconut diethanolamide. From Blakeway et al. [205].

Chem. Descrip. Lauryl ether sulphate (3 EO), ammonium salt and otg. solv. 

Zarapkar, S. S., K. R. Athalye, Titrimetric method for determination of sodium lauryl sulphate, sodium lauryl ether sulphate, triethanolamine lauryl sulphate and alkylbenzene sulpho-nate by titration with centrimide, domiphen bromide and oxyphenonium bromide using cobalt thiocyanate indicator. Soaps, Deterg. Toiletries Rev., 1987,17rfO), 21-23. 

A key attribute of ether carboxylates is mildness which increases with EO number but this can also reduce detergency. Comparing sodium salts with a predominantly C12 alkyl chain, the 3-mol carboxylate would have a Zein score of 150, while the 13-mol one would score 80 (cf. laureth-2 sulphate at 270 and sodium lauryl sulphate at 490) [9]. The sodium salts show phase behaviour similar to ether sulphates but the position and scale of the viscosity minimum can be varied with C chain, degree of ethoxylation and, unlike ether sulphates, by the degree of neutralisation [9]. 

Polarographic measurements were carried out in an acetate buffer (the assumed pH was 3.66), and concentrations of sulphate and acetate were varied in the presence of l.OOx lO M nickel nitrate and 1.09 x 10 M nitrilotriacetate at a constant ionic strength of 0.2 M (maintained with potassium nitrate). A dropping mercury electrode was used, and polyoxyethylene lauryl ether (1-2 x 10 M) was used as a maximum suppressor. Although results are reported for 15, 25 and 35°C, the assumed pH value for the buffer at 15 and 35°C is not stated. The acetate molarities were varied from 0.025 to 0.100 M at 0.03 M sulphate, and the potassium sulphate molarities were varied from 0.01 to 0.05 M at 0.05 M acetate. The results indicated that for the experimental... 

The bromination of phenyl n-pentyl ether is more para-selective in anionic micelles than it is in water. This contrasts with the lower para-selectivity of nitration of bromobenzene in the cationic micelles formed by dissolving lauric acid in 95% H2S04. It is not clear whether these effects are due to substrate orientation or to micelle-induced changes in the selectivity parameter for electrophilic aromatic substitution. The rates of solvolysis of alkyl p-trimethyl-ammoniumbenzenesulphonate trifluoromethanesulphonates (42) are strongly inhibited by anionic micelles of sodium lauryl sulphate or sodium dodecanoate. In water, homomicelles of (42) or sodium dodecanoate micelles, undergo inversion of stereochemistry, but in sodium lauryl sulphate 22% retention of... 

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