Preparation of a Gemini Surfactant from Mixed Fatty Acid and its Use in Cosmetics

Among the surfactants, dimeric surfactants represent a niche group with multifunctional properties. In this work a modified gemini surfactant was synthesized using symmetrical fatty acids. Due to the spacers used to combine the two symmetrical monomers, the synthesized gemini surfactant is cationic. The structure of the compound was confirmed with 1H-NMR. The most advantageous property of the gemini surfactant is that it has a lower surface tension, i. e. less than 35 mNm–1 at 25°C, compared to monomeric surfactants. The surface tension was determined with a Kyowa tensiometer. The CMC (critical micelle formation concentration) was calculated according to the pyrene method and detected by UV spectroscopy at 25°C. The very low CMC is another market advantage of the gemini surfactant. Hydrophobicity and hydrophilicity of the synthesized compound were checked by the emulsification method. The ability of the synthesized gemini surfactant to wet and foam and the emulsification index at different pH values were tested. Based on the results, the gemini surfactant was used in formulations for hair and skin care. Conditioners and creams were prepared with the synthesized compound and the properties were analyzed at different concentrations of the gemini surfactant in the respective formulation.

Efficiency of single and mixed dimeric surfactants micelles on solubil-ization of polycyclic aromatic hydrocarbons

The solubilization of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene and pyrene by single and mixed anionic dimeric surfactants was investigated and correlated with micellar properties of these surfactants. The surface and micellar properties of single and binary mixed combinations of anionic dimeric surfactants have been studied through surface tension as well as conductivity measurements at 300 K. The associations between their micelle properties and solubilizing efficiency towards PAHs have been quantified and discussed in terms of the molar solubilization ratio (MSR), micelle-water partition coefficient (Km) and standard free energy of solubilization (ΔG0S).The negative value of ΔG0Sexhibits spontaneously the solubilization process. The MSR values increase with the order “pyrene < phenanthrene < naphthalene”. The current study provides significant information for the selection of mixed dimeric surfactants for solubilizing water-insoluble compounds.

Synthesis of functionalized by an oxime group surfactants on the basis of imidazole, pyridine and alkylamines

Methods have been developed for the synthe-sis of a series of monomeric and dimeric surfactants functionalized by an oxime group based on imid-azole, pyridine and alkylamines. Alkyl radicals of varying degrees of branching were used, both as sub-stituents at the nitrogen atom of the head group and as spacers in the formation of dimeric products. This allowed to create a whole spectrum of supramo-lecular systems with different physicochemical pro-perties and reactivity.Methods of obtaining a number of intermedi-ate products were improved, primarily for the reac-tion of the imidazole alkylation using interphase ca-talysis conditons — solid phase-liquid. The method of obtaining surfactants based on imidazole consisted in the interaction of alkylimidazoles with chloro-acetaloxime in a suitable solvent or with chloro-acetone and subsequent reaction with a hydroxyla-mine solution. In the preparation of pyridine-based surfactants, the corresponding oxo-substituted pyri-dine was reacted with a hydroxylamine solution, fol-lowed by reaction of the obtained product with al-kyl halide. A method has been developed for the syn-thesis of functionalized surfactants based on alipha-tic amines, where for monomeric products a path is chosen that is associated with the sequential alkyla-tion of 1-chloroacetoxime with dimethylamine and dodecyl bromide, and for dimeric ones, the direct interaction of 1,3-dichloroacetoxime with 1,1-dime-thyl-1-dodecylamine.The composition, structure and purity of the obtained compounds were confirmed by NMR spec-troscopy, thin-layer chromatography and elemental analysis. NMR spectra were recorded on a BRUKER Avance II 400 instrument (400 MHz), TMS was used as an internal standard. Chromatography in a thin layer of silica gel was performed on Merck Si-licaGel 60 F254 plates (eluent — chloroform: meth-anol = 10:1).The data presented by us testify to the pro-spects of the chosen pathway for structural modifica-tion of surfactants functionalized by the oxime group, and give direction for the further design of such microheterogeneous systems.

SYNTESIS of DIMERIC SURFACTANTS based on SYNTHANOL DS-10 AND ADIPINIC ACID

Mono- and di- esters of adipinic acid with long chain ethoxylated aliphatic alcohols (mixture of C10 – C12 and C16 – C18 alkohols) were obtained by the reaction of Synthanol DS-10 and adipinic acid and its dichloroanhydride. If adipinic acid with p-toluenesulfonic acid as catalyst were used as acylating agent and the mole ratio of Synthanol DS-10 to adipinic acid is 1:1 the yield of monoacylated product was 76 %. (temperature 120-125 °C, 3 h). If the mole ratio of Synthanol DS-10 to adipinic acid is 2:1 the yield of diacylated product was 80 % (temperature 120-125 °C, 6 h). Using dichloroanhydride of adipinic acid as acylating agent gives the 90 % (temperature 90-100 °C, 7.5 h) yield of diacylated product. The structure of all compounds was established by IR and NMR spectroscopy. Surface tension dependence on concentration in aqueous and alkaline medium was investigated for the obtained compounds. It was determined that the colloidal properties of the synthesized products differ significantly from the original Synthanol DS-10. The minimal surface tension of synthesized compounds is 25-33 mN/m. The surface activity of monoester in 5 % sodium hydroxide is 5.74 N·m2·mol-1 (for Synthanol DS-10 3.06 N·m2·mol-1). But in water their surface activity is 4.00 and 4.17, respectively. Opacity temperature in different mediums was established for the new compounds. Cloud point at the concentration of 0.25 g/dm3 of diester of adipinic acid in water (>100 °C) is significantly higher than for Synthanol DS-10 (81 °C) and for monoester (46 °C). In 5 % solution of sodium hydroxide the cloud points of all these compounds are the same (difference is 2-3 °C). The new products are stable in water and alkaline medium, but not stable in 0.1N solution of hydrochloric acid. The new synthesized surfactants from Synthanol DS-10 and adipinic acid (by the complex of colloidal and physical-chemical properties) are interesting as the ingredients of technical and household compositions. Forcitation:Lominoga E.A., Burmistrov K.S., Gevod V.S. Syntesis of dimeric surfactants based on synthanol DS-10 and adipinic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N2. P. 91-96