Surfactants from oleic, erucic and petroselinic acid: Synthesis and properties

Abstract

Most surfactants are based on C₁₂ and C₁₄ chains from fatty acids and contain alkanols obtained from ethylene. Readily available fatty acids with C₁₈ and C₂₂ chains are barely used due to their lower water solubility and less suitable structure for micelle formation. To overcome these deficiencies, we attached polar groups to terminal and/or internal positions of oleic, petroselinic and erucic acid. Internal diols were prepared by epoxidation and acid-catalyzed ring opening or by bishydroxylation with catalytic amounts of osmium tetroxide. Terminal alcohols were prepared by reduction of the methyl esters. For the synthesis of the non-ionic surfactants, the alcohols were reacted with the p-toluenesulfonates of di-, tri- and tetraethyleneglycols or the epoxide ring was opened with the corresponding oligoethyleneglycols. This way, ethoxylates free of homologues were obtained. Sodium sulfate surfactants were prepared by reacting the mono-, di- and triols with different equivalents of chlorosulfonic acid. From the purified products, the spectroscopic and the surfactant properties were determined. The latter are in many cases equal or better than those of commercial ionic and non-ionic surfactants based on C₁₂ and C₁₄ carbon chains.