Synthesis and properties of a novel asymmetric gemini surfactant based on siloxane skeleton

Abstract

The paper introduced a kind of hydrogen-containing epoxy polysiloxane skeleton of different chain lengths with a defined molecular weight. Based on the skeleton, a novel asymmetric gemini siloxane surfactant (AGSS) was synthesized by reacting with maleic anhydride monoester and taurine. The chemical structure of AGSS was characterized by 1H NMR and FT-IR. At the same time, the physical and chemical properties of the three oil displacants were systematically studied. The results show that the minimum surface tension of the series of oil displacing agents is 29.02 mN/m, and the corresponding critical micelle concentration (cmc) is 0.416 mmol/L. As the silica chain in the polysiloxane backbone increases from n = 0 to n = 8, the surface tension corresponding to the critical micelle concentration decreases, much lower than conventional hydrocarbon surfactants. Besides, the study results show that the AGSS have good temperature resistance, salt resistance and resistance to divalent ions (Ca2+, Mg2+), and the above properties meet the needs of oil displacement applications.