Synthesis and Study of 4, 4-12-12 Alkyl Phenol Polyoxyethylene Sulfonate Gemini Surfactant

Background: Gemini surfactants have good prospect of application development in various fields for their superior performance in foaming, wettability, and emulsification with lower critical micelle concentration (CMC) than conventional mono-surfactants. Objective: The purpose of this study was to synthesize an ionic sulfonate Gemini surfactant, which is mainly used as an oil flooding agent, to improve oil recovery and reduce oil production cost. Methods: With 4-dodecyl phenol, diethylene glycol and triethylene glycol as the raw materials to synthesize two sulfonate Gemini surfactants. The single factor experiment combined with Box-Behnken center composite experimental design, the optimum reaction conditions were determined. The optimal reaction condition of sulfonation was determined by orthogonal test. The product structure was characterized by nuclear magnetic resonance and infrared. Results: The mass fraction of sodium hydroxide ω(NaOH), temperature and the quality ratio of hexadecyl trimethyl ammonium bromide to dodecyl phenol were 18%, 93.5°C and 14.2%, respectively. Under the condition of ice bath, the molar ratio of chlorosulfonic acid to 4, 4- 12-12 alkyl phenol polyoxyethylene ether was 2.02:1 and reaction for 5h. The critical micelle concentration was determined to be 2×10-4, 1.05×10-4, respectively. Conclusion: Two sulfonate Gemini surfactants, namely 5, 5-dilauryl alkyl-2,2'-(diethylene glycol oxygen base) sodium diphenyl sulfonate and 5,5-dilauryl alkyl-2,2'-(triethylene glycol oxygen base) sodium diphenyl sulfonate (recorded as III and IV, respectively) were synthesized. The synthesized surfactants have excellent emulsification ability.