Synthesis and high-performance of a new sarcosinate anionic surfactant with a long unsaturated tail

Abstract

A new C₂₂ tailed sarcosinate anionic surfactant, 2-(N-erucacyl-N-methyl amido) acetate (EMAA), has been synthesized by use of the erucic acid and a hydrotrope—sarcosine. In contrast to the common method, which blends the hydrotrope with a surfactant, the sarcosine has been introduced into the anionic surfactant through chemical modification. Interestingly, the resultant C₂₂ tailed anionic surfactant shows excellent water solubility despite the ultra-long alkyl chain. Besides, the EMAA also exhibits high surface activity, and pH controllable micelles to vesicles transition (MVT). Rheology studies have revealed that the rheological properties of EMAA solutions are influenced by the concentration, temperature, salt, and pH dramatically. Aside from the excellent water solubility, the original feature highlighted in this work is that such a new C₂₂ tailed sarcosinate anionic surfactant exhibits good temperature resistance. Compared to the potassium oleate (KOA), the zero-shear viscosity of the EMAA solution is nearly 3 orders of magnitude higher under the same conditions.