Synthesis and Properties of Novel Catanionic Surfactant Phosphonium Benzene Sulfonate

Abstract

A new type of catanionic surfactant phosphonium benzene sulfonate was synthesized by quaternization of triphenyl phosphine with dimethyl carbonate and followed by anion exchange with alkyl benzene sulfonic acid. The molecular structure was characterized by FT-IR, 1H-NMR, and 31P-NMR. The thermal stability of phosphonium benzene sulfonate was evaluated by thermogravimetric analysis (TGA). Its surface properties were studied systematically through equilibrium surface tension, electrical conductivity, and dynamic surface tension measurements. The wettability, foam properties, and emulsification of phosphonium benzene sulfonate were estimated in this paper. TGA results revealed that it has an excellent thermostability and could be used below 350 °C. Equilibrium surface tension results indicated that it has a low critical micelle concentration (CMC, about 0.10 mmol/L), lower than that of ammonium benzene sulfonate and sodium dodecyl benzene sulfonate. Furthermore, the micellization of phosphonium benzene sulfonate in aqueous solution is an entropy-driven spontaneous process. The adsorption process of phosphonium benzenesulfonate at the air-liquid interface is controlled by hybrid kinetic adsorption. Moreover, it has excellent wetting and emulsifying properties and low foam properties.