Synthesis and Surface Activity of Guerbet Betaine Surfactants with Ethylene Oxide Groups

Abstract

Abstract Three series of Guerbet betaine surfactants with ethylene oxide groups were synthesized by Guerbet alkyl polyoxyethylene ether surfactants, epichlorohydrin, dimethylamine and sodium chloro-acetate. Their structures were confirmed by MS. The critical micelle concentrations (CMC) and surface tension at CMC (γ CMC ) of all prepared Guerbet betaine surfactants were determined by K100C processor tensiometer with the Wilhelmy-plate method at 25°C. It is found that synthesized surfactants exhibit great efficiency of reducing surface tension. As the number of ethylene oxide groups increases, the γ CMC gradually increases. As the length of the hydrophobic chain of Guerbet betaine surfactants increases, the γ CMC increases firstly and then decreases.