Interactions of a widely used commercial anionic surfactant, linear alkylbenzene sulfonate, with zein protein, a water insoluble protein, was studied to better understand the effects of the counterion on skin irritation of anionic surfactants. The neutralizing ions used were inorganics: Li+, Na+, K+, Mg2+, and NH4+ and organics: monoethanolamine, diethanolamine, and triethanolamine. According to the results obtained, the influence of counterions of anionic surfactants on zein solubilization is significant; with magnesium counterions showing lower zein solubilization. In aqueous solutions, zein solubilization by anionic surfactant is related to the effect of the counterion on the critical micelle concentration of the surfactant for the inorganic counter‐ions; for the organic counter‐ions, effects of tighter anionic binding in the micelle also contribute to zein solubilization trends.

Sulfoxidation of fatty acid methyl esters with SO 2, O 2 and ultraviolet light of appropriate wavelength, has led to the synthesis of methyl esters sulfonates or sulfoxylates, known as U-MES, because of the possible random position of SO 3 group in the alkyl chain. Aqueous solutions based on the sulfoxylated methyl ester of palmitic acid (U-MES C16) have been studied and compared to the leading types of surfactants used today: linear alkylbenzene sulfonate (LAS) secondary alkane sulfonate (SAS) and asulfo fatty methyl ester sulfonate (a-MES) with regard to solubility, performance and skin compatibility. The experimental results obtained indicate that U-MES C16 can be regarded as a potential component of detergent formulations and most likely also of body care products.

Sulfoxidation of fatty methyl esters with SO 2 , O 2 , and ultraviolet light of appropriate wavelength has led to a synthesis of sodium methyl ester sulfonates known as Φ-MES. The designation of Φ refers to the random positioning of SO 3 in the alkyl chain. This investigation describes for the first time the operating conditions necessary to produce these new anionic surfactants as well as the analytical methods used in their isolation, analysis, identification. Some surface properties are discussed as well. JSD 1, 335-341 (1998). FIG. 1. Infrared spectra of sodium methyl ester sulfonates (Φ-MES, -) and of α-sulfo fatty methyl esters (α-MES, -·-·-) with C16 chain lengths.

This paper deals with the separation and purification of Φ-methyl ester sulfoxylates obtained through the sulfoxidation process. Two new steps are implemented during separation of the final product from the nonreacted reagent: (i) hot water is used instead of water/ethanol mixture, and (ii) n-butanol is used as the extractive phase after neutralization instead of ethanol, leading to a product with more than 75% active ingredient. A significant improvement in the separation and purification steps has been obtained. The new procedure allows a complete material balance of the main products formed during sulfoxidation of fatty acid methyl esters and thus can lead to study of the reaction conditions, which can improve both conversion and selectivity.Paper no. S1195 in JSD 4, 73-74 (January 2001).KEY WORDS: Extraction, Φ-MES, separation.Φ-Ester sulfoxylates (Φ-MES) are new anionic surfactants obtained through sulfoxidation of fatty acid methyl esters with SO 2 , O 2 , and ultraviolet light of appropriate wavelength. The operating conditions for the synthesis of Φ-MES and the analytical network for its separation and purification have been documented (1). Nevertheless, further work has been performed to improve the separation and extraction processes. After completion of the sulfoxidation reaction, the reactor product contains mainly mono-and polysulfonic acids; some fatty acids, most probably resulting from fatty methyl ester hydrolysis; some sulfuric acid; and all the nonreacted fatty acid methyl ester since the reaction conversion is close to 30% w/w. It is therefore necessary first to separate the nonreacted methyl ester from the reaction products in order to recover the former for further synthesis. In previous work, the separation procedure proposed has some weaknesses (1). The separation of Φ-MES from the nonreacted methyl ester with a mixture of water/ethanol yields, an organic phase and an acidic phase. However, by this procedure, the separation is incomplete, leaving some impurities in both the acidic and the organic phases. Furthermore, some fatty acid remains in the acid phase, leading to a final product with a significant soap content.After the separation is carried out, the desired product has to be separated from the unwanted materials such as fatty acid, sulfuric acid and other nonidentified impurities. For purification, the previous method (1) uses ethanol as the extractive phase after neutralization of the acidic phase and dryness. This procedure is time-consuming (several days), and many of the impurities soluble in ethanol are extracted as well, making it impossible to obtain a final Φ-MES product with more than 40% active ingredient. All of these problems have been overcome with the methodology presented herein. MATERIALS AND METHODSSeparation procedure. The analytical network shown in Scheme 1 depicts two new methods for the separation of the reacted from the nonreacted products, which are mainly Φ-MES sulfonic acid (mono-and polysulfonic acids), fatty acid and nonreacted methyl ester: the hot wate...

Sulfoxidation of fatty acid methyl esters with SO 2 , O 2 , and ultraviolet light of appropriate wavelength has led to the synthesis of methyl esters sulfonates or sulfoxylates known as Φ-MES because of the possible random position of SO 3 group in the alkyl chain. This work describes experimental measurements of physical properties such as solubility and viscosity of sodium Φ-MES water solutions. Amphipathic properties such as surface tension, critical micelle concentration, wetting and foaming powers were measured as well and compared to linear alkylbenzene sodium sulfonate (LAS). Finally, stability to water hardness, dishwashing test, and detergency performance were evaluated. Expectedly, these products may be used as LAS partners either in heavy-duty powders or in hand dishwashing liquids. Experimental results on Φ-MES of varying carbon number indicate that C 16 is the optimal carbon chain length.