Lauryl ether sulfate

When ammonium lauryl sulfate is reacted with ethylene oxide, the result is the larger molecule ammonium laureth sulfate. This molecule has the same detergent and surfactant qualities, but it is larger consequently it does not penetrate the skin and hair as easily. The term laureth is actually a contraction of lauryl ether. The full name is ammonium lauryl ether sulfate. 

The most common ingredient in shampoos is also the most common detergent in use in other products a class of surfactants known as straight-chain alkyl benzene sulfonates. Examples are ammonium lauryl sulfate, its sodium relative, and the slightly larger but related molecule ammonium lauryl ether sulfate (sometimes abbreviated as ammonium laureth sulfate). 

Sanchez et al. [61,62] studied the stability of sodium decyl, dodecyl, and tetradecyl sulfates and sodium lauryl ether (3 EO) sulfate in acid media (pH 1) at different temperatures and concentrations above and below the critical micelle concentration. Sodium decyl sulfate was shown to be relatively stable for several hours at temperatures up to 90°C. Sodium dodecyl and tetradecyl sulfates were only stable for short periods of time at temperatures above 40-50°C. As expected, sodium lauryl ether sulfate was less stable to hydrolysis than the corresponding lauryl sulfate. 

One-phase titration methods have also been developed. These methods are not truly one-phase titrations but the term is used to indicate the absence of a second organic phase. One of these methods, applied to the analysis of sodium and triethanolamine lauryl sulfates and lauryl ether sulfates, use a quaternary amine as a titrant and cobalt(II) thiocyanate as indicator. Centrimide was found to avoid the use of chloroform which was not possible with other titrants examined, such as domiphen bromide and oxyphenonium bromide. The pink color of the indicator changes to violet as an excess of titrant forms a complex with the indicator [238]. 

Comparison of C12-C14 polyether carboxylates with 3, 4, and 5 mol EO with sodium lauryl ether sulfate (2 mol EO) indicated approximately the same detergency and a little better wetting using the ether carboxylates, with the remark that 4 EO gave the optimum [10]. 

FIG. 3 Lime soap dispersing power of some alkyl ether carboxylates compared to other surfactants (DIN 53903). AEC, alkyl ether carboxylate AMEC, amidether carboxylate CAPB, cocamidoproplylbetaine OEC, oleyl ether carboxylate SLES, sodium lauryl ether sulfate. % surfactant soap = % surfactant calculated on the soap needed to disperse the lime soap. (From Refs. 61 and 64.)... 

TABLE 9 Foaming Characteristics of Mixtures of Na Lauryl Ether Sulfate (SLES + 2 EO) and Na Lauryl Ether Carboxylate (Cl2-C 4 13 EO CH2COONa) According to R M... 

In 1973 it was published that in contrast to lauryl ether sulfate the lauryl ether carboxylic acid sodium salt with 3 mol EO did not disturb the skin s water loss and did not decrease the skin s resistance [74], Formulation tests for the use as emulsifier in creams were described in 1976 [75]. 

Van Paassen [57,67] reported a synergistic decrease of the skin and eye irritation level of sodium lauryl ether sulfate by combination with lauryl ether carboxylates. The investigations have been carried out using the Draize eye irritation test and human patch test (Tables 13 and 14). Furthermore, measurements by in vitro methods, the Zein test, and the red blood cell test show low to no irritancy [251-253]. 

TABLE 13 Synergistic Decrease of Eye Irritation Level of Sodium Lauryl Ether Sulfate (SLES 2 EO) by Sodium Lauryl Ether Carboxylate... 

DLSS, DPMS, DSIS, and a blend containing SLAS and DCAD are the components to improve the formulations skin mildness, i.e., the skin compatibility of the other surfactants present. SLES/ALAS/SLAS, i.e., sodium lauryl ether sulfate, ammonium lauryl sulfate, sodium lauryl sulfate, are examples of high-foaming basic surfactants. 

Water serves as a base value in this test and sodium lauryl sulfate as a well-known irritating surfactant. Lauryl ether sulfate served as a substance with high sales volume and good skin tolerance. As was to be expected, lauryl ether sulfate scored only slightly better than lauryl sulfate. Sulfosuccinate values obtained were classified under little skin roughening effect. ... 

Sulfosuccinates are not only less irritating to skin and mucus membranes than other surfactants, but it was also found that they reduce skin irritation of other surfactants used in skin and hair care products. In particular, the effect on sodium lauryl ether sulfate was found to be most pronounced [103]. Figure 14 shows the mollifying effect of disodium oleic acid monoethanol amide sulfo-succinate when blended with anionic surfactant at a total concentration of 15%. 

Similar results have been obtained at Witco with eye irritation tests on mixtures made from sodium lauryl ether sulfate and the sodium salt of a sulfosuccinate monoester [105], as shown in Fig. 15. Figure 16 shows one third re-... 

Witco s results employing the Zein test are depicted in Fig. 17. Other authors assessments [16] with respect to lauryl ether sulfates, lauryl sulfate, and sulfosuccinates have been confirmed. 

When sodium lauryl ether sulfate (FAES) is produced at high concentration, the concentrated paste may contain a small quantity of air. A continuous FAES paste deaeration unit can be installed to remove the air under reduced pressure in a special facility located downstream from the neutralization so as to ensure the production of a completely translucent paste. 

Sodium Metasilicate Sodium Tripolyphosphate Tetrapotassiurn Pyrophosphate Sodium Lauryl Ether Sulfate Sol in (35%)... 

A 62 35 3 ethyl acrylate-methyl methacrylate-acrylic acid copolymer latex was prepared by continuous addition of the monomer mixture over a 4-hour period at 80° (22). The emulsifier was a sodium lauryl ether sulfate-nonylphenol polyoxyethylene adduct (20 moles ethylene oxide) mixture, the initiator a potassium persulfate-sodium hydroxulfite mixture, and the buffer a sodium bicarbonate-potassium hydroxide mixture. The final latex of pH 6.5 contained 40% solids, and the Tg of the copolymer was 13°. 

The material balance of the strong-acid groups showed a theoretical total of 0.194 meq/gm polymer from the sodium lauryl ether sulfate, potassium persulfate, and sodium hydrosulfite, in comparison with a measured total of 0.205 meq/gm (0.026 on particle surface 0.179 in serum) by serum replacement and a total of 0.215 meq/gm by ion exchange with Dowex 50W(H+). The material balance of the acrylic acid showed that 29.9% was on the particle surface, 28.6% in the aqueous serum, and 41.5% buried inside the particle. The sodium lauryl ether sulfate found in the serum amounted to 78% of that added by Hyamine 1622 titration and 88% by thin-film chromatography. The nonylphenol polyoxyethylene adduct amounted to 113% by iodine-iodide titration and 91% by thin-film chromatography. ... 

Thus these characterization results not only give the distribution of the acrylic acid between the aqueous serum, particle surface, and particle interior, but also account satisfactorily for the total number of strong-acid groups arising from the anionic emulsifier and initiator. In addition, both the sodium lauryl ether sulfate and the nonylphenol polyoxyethylene adduct used in the polymerization were recovered from the fractions obtained by serum replacement. 

CAPB = Coco amido propyl betaine, SLES = Sodium lauryl ether sulfate, MAP = Mono alkyl phosphate, SDS = Sodium dodecyl sulfate... 

Highly active (69%) ammonium lauryl ether sulfate. 

Aqueous solutions (28%) of sodium lauryl ether sulfate. 

Highly active (6970%) sodium lauryl ether sulfates. 

Ammonium lauryl ether sulfate EMPICOL Albright Wilson... 

Surfactants anionics sodium lauryl ether sulfate (SLES) and sodium lauryl sulfate (SLS) amphoteric cocamidopropyl betaine (CAPB) nonionic alkyl polyglucoside (APG). 

Anionic Ammonium lauryl sulfate (ALS) Ammonium laureth sulfate Sodium lauryl sulfate (SLS) Sodium lauryl ether sulfate (SLES) Alpha olefin sulfonate (AOS) Sodium cocoyl isethionate Sodium isethionate Sodium afkylbenzene sulfonate Sodium lauryl sacorsinate Sodium lauryl lactate Sodium lauroamphoacetate... 

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