Synthesis of Gemini oxalamide hexyl succinate sodium sulfonate

Using maleic anhydride,ethylenediamine,hexanol,sodium sulfite as the starting materials,the Gemini surfactant of oxalamide hexyl succinate sodium sulfonate was synthesized successfully through amidation,esterification and sulfonation reactions.The best reaction conditions for synthesis of the target product were obtained by the single factor optimization method.The amidation reaction was carried out by refluxing the reaction mixture in acetone for 80 minutes at a ratio of n(maleic anhydride):n(ethylenediamine)=2.2:1,with the product yield reaching about 96%.The esterification reaction was carried out at a ratio of n(hexanol):n(ethylenediamine)=2.2:1 at 130 ℃ for 150 minutes,with the yield of esterification product reaching about 90%.The sulfonation reaction was carried out at a ratio of n(sodium sulfite):n(ethylenediamine)=2.2:1 at 100 ℃ for 3 h,with the yield of sulfonation product reaching about 90%.Then,the product was characterized by the IR spectroscopy,and the results showed that the product was the expected target product.The measurement of interfacial tension showed that the Gemini surfactant had lower critical micelle concentration and interfacial tension.