Surface‐active properties of novel cationic surfactants with two alkyl chains and two ammonio groups

A series ofbis‐quaternary ammonium salts was easily prepared by the reaction of a long‐chaintert‐alkylamine with epichlorohydrin, and their surface‐active properties were measured. The prepared amphipathic compounds had good water solubility and showed characteristic surface‐active properties, particularly, extremely excellent foaming ability and foam stability for some specific compounds, such as the compound with a dodecyl and a tetradecyl group as the lipophilic chains. Their critical micelle concentration, which decreased with increased alkyl chainlength, is two orders of magnitude lower compared with the conventionalmono‐quaternary ammonium salts. In comparison with surface‐active properties ofbis‐quaternary ammonium salts, prepared from various organic dichlorides, there are little differences based on the kind of connecting group in the surface‐active properties except for foaming.