Study on the synthesis and performance of sodium 2-laurylamido isobutyrate

Abstract

Abstract In the present work, sodium 2-laurylamido isobutyrate was synthesized from 2-aminoisobutyric acid, NaOH and lauroyl chloride by the Schotten-Baumann condensation. Fourier transform infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectroscopy were used to characterize the products, and confirming the successful synthesis of sodium 2-laurylamido isobutyrate. The influence of temperature on the surface tension of sodium 2-laurylamido isobutyrate was studied, comparing the chemical properties of the surface with those of sodium N-lauroyl sarcosinate. The results indicate that both surfactants have a similar pC 20, while the critical micelle concentration (CMC) and the surface tension at the critical micelle concentration (γ CMC) of sodium 2-laurylamido isobutyrate are higher than those of sodium N-lauroyl sarcosinate. Further studies on the thermodynamic parameters of sodium 2-laurylamido isobutyrate and sodium N-lauroyl sarcosinate indicate that the formation of micelles is a spontaneous exothermic process mainly driven by entropy. According to the dynamic surface tension of sodium 2-laurylamido isobutyrate and sodium N-lauroyl sarcosinate, the molecular adsorption of the two components mixture change from the initial diffusion controlled adsorption to the later mixed dynamic controlled adsorption.