Isethionates Applications

While there was a growing number of non-soap detergents that either were already commercialized (as for use in laundry applications) or else had viable commercial potential, it was decided early on to limit the compositional search space to compositions using sodium acyl isethionates (SAI) as the primary surfactant. This decision was based on an early assessment of a prototype bar containing SAI which had been described in a 1952 French patent for which Unilever had acquired the rights [9], This prototype bar, with composition as described in Table 9.2-2, was referred to as the Monsavon bar. 

Several other anionic surfactants are commercially available, such as sulfosuccinates, isethionates, and taurates, and these are sometimes used for special applications. The carboxylates and sulfates are sometimes modified by the incorporation of a few moles of ethylene oxide (referred to as ether carboxylates and ether sulfates, respectively). 

Despite its potential application to charged surfactant analysis, there have been relatively few publications of ion chromatography applications. Dionex in their applications literature demonstrate several possible separations including alkyl sulphates the separation of sodium isethion-ate from its alkyl isethionate ester on a Vydac 302 IC column with methanol 20mM phthalic acid water (3 5 12, 2.5) and conductivity detection is described in [49]. 

Several other anionic surfactants are commercially available such as sulfosuccinates, isethionates and taurates and these are sometimes used for special applications. 

Applications. Acyl isethionates have been used in shampoos and personal cleansers. They are also incorporated in syndet bars, together with various soaps. 

This class of specialty surfactants consists of the fatty acid esters of isethionic acid (2-hydroxyethane sulfonic acid). They have good foaming and dispersing properties and are suitable for synthetic bar soap and cosmetic applications. The ammonium salts are very water soluble (-30%), whereas the sodium salts are not (-0.1%). Commercial products are generally made with coco fatty acids and contain residual free fatty acid in the 10% range. 

These are named as derivatives of taurine (2-aminoethanesulfonic acid) and are also called taurides. The typical synthetic route involves reaction of sodium bisulfite and ethylene oxide to form sodium isethionate, reaction of the isethionate with methylamine to form sodium iV-methyltaurate, then subsequent reaction with the acyl chloride of a fatty acid to give the iV-acyl-Al-methyltaurate. Taurates have good tolerance to water hardness and find specialty applications in textiles and in detergent bars and shampoos. Taurates are sometimes classified as amphoteric surfactants. 

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