Abstract:In order to research the properties of long-chain amidopropyl sulfobetaines, three kinds of long alkyl chain amidopropyl sulfobetaines were prepared from methyl stearate, methyl oleate, 11-(3,4-dimethyl-phenyl)-stearic acid methyl ester, 3-dimethylaminopropylamine and 1,3-propane sultone by two-step reaction, and the structures were confirmed by 1HNMR and mass spectrometry through the surface tension, salt resistance, foam performance, oil-water interfacial tension performance tests, it is found that the three long alkyl chain amidopropyl sulfobetaines have good surface/interface activity, foam stability, emulsifying ability, resistance ability to salts; introducing aralkyl groups into long alkyl chains enhanced the surface activity of 11-(3,4-Dimethyl-phenyl)-octadecylamidopropyl-N,N-dimethylsulfobetaine (C18DAMSB), the critical micelle concentration and surface tension were 1.57×10-5 mol/L and 28.98 mN/m, both lower than oleic acid amidopropyl sulfobetaine (UC18AMP3SB) and stearic acid amidopropyl sulfobetaine (R18DMSA); the double bond in the hydrophobic chain of UC18AMP3SB makes its salt tolerance better than C18DAMSB and R18DMSA.