- Synthesis and surface activities of amidobetaine surfactants with ultra-long unsaturated hydrophobic chains
-
Recent studies have shown that the surfactants bearing an ultra-long hydrophobic chain (>C18) exhibit unique self-assembly properties. However, their synthesis and surface activities have been less documented. In this work, monounsaturated alkyl dimethyl amidopropyl betaines, UCnDAB (n = 18, 22, and 24), were prepared by the reaction of the corresponding fatty acids with N,N-dimethyl-1,3-propanediamine, followed by quaternization with sodium choloroacetate of the obtained intermediates. The intermediates and final surfactants were characterized by 1H NMR and ESI-HRMS, respectively. Krafft temperature (TK) and surface activities of the surfactants were also examined. It was found that TK of all these surfactants is lower than 0°C, and their critical micellar concentration (CMC) is within the range of 10-3 mmol/L. In addition, the linear relationship between lg CMC and n is still in evidence.
- Feng, Dan,Zhang, Yongmin,Chen, Quansheng,Wang, Jiyu,Li, Bin,Feng, Yujun
-
p. 657 - 661
(2012/11/07)
-
