Synthesis and surface properties of several nonionic–anionic surfactants with straight chain alkyl-benzyl hydrophobic group

New nonionic–anionic surfactants of sodium straight chain alkyl benzyl alcohol homogeneous polyoxyethylenated propane sulfonates (ABEPS) were synthesized by the reaction of long chain alkyl (octyl, decyl and lauryl) benzyl chlorine with tri(ethylene glycol), followed by the reaction with 1,3-propane sultone. The physicochemical properties of ABEPS (e.g. Krafft temperature and equilibrium surface tension) have been measured. ABEPS shows favorable solubility, and all of the Krafft temperatures are below 0 °C. With increasing alkyl chain length, the critical micelle concentration (CMC), surface tension at CMC (γCMC) and surface area per molecule (Amin) of ABEPS decrease, and the efficiency in reducing surface tension (pC20) and adsorption at the air/water interface relation to micellization (CMC/C20) increase clearly. Compared with fat alcohol ether sulfates with an analogous number of carbon atoms in hydrophobic group, the values of pC20 and CMC/C20 for ABEPS were more predominant. Moreover, these surfactants in the article show the character of both nonionic and ionic surfactants due to its particular molecular structure.