Synthesis and Properties of Amphoteric Amide Surfactants with Reactive Group

Abstract

Abstract Three reactive amphoteric surfactants (M10, M12 and M14) with different alkyl chain lengths have been synthesized using N,N'-dimethyl-1,3-propyldiamine, maleic anhydride and alkyl bromide as raw materials. The compounds had been characterized by mass spectrometry and 1H-NMR. The critical micelle concentration (CMC) and the corresponding surface tension (γCMC) of M10, M12 and M14 were measured at temperatures from 298 K to 313 K. The results showed that the CMC of M10, M12 and M14 are 5,89 × 10−4 mol L−1, 2,63 × 10−4 mol L−1 and 1,35 × 10−4 mol L−1. The γCMC of M10, M12 and M14 are 31.26 mN m−1, 28.79 mN m−1, and 26.87 mN m−1 at 298 K respectively. As the temperature rises, the CMC and the minimum molecule area (Amin) increased gradually, but the γCMC and the maximum surface adsorption capacity (Γmax) decreased moderately. The micelle aggregation number (Nm) was determined and changed slightly in the temperature range of 298 K–313 K, which showed that the micelle aggregation number was insensitive to the temperature change.