A novel cationic surfactant having two quaternary ammonium ions

Novel cationic surfactants having two hydrophobic groups and two quaternary ammonium ions which are in the middle of alkyl group were prepared by two-step reactions. Three kinds of N,N-bis-(3-n-alkoxy-2-hydroxypropyl)-N,N-dimethyl-1,3-propylenediamine were prepared quantitatively as the intermediate by the condensation reaction between alkyl glycidyl ether and 3-(dimethylamino)-1-propylamine under mild conditions without solvent and catalyst. The intermediates were quaternized with dimethyl sulfate. The structures of the products were characterized by 1H NMR, FAB/MS and FT-IR. The interfacial properties of the synthesized cationic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle and foam stability.