Synthesis and Solution Properties of Nonionic Hybrid Surfactants with a Benzene Ring

Abstract

Four nonionic hybrid surfactants with a benzene ring as a spacer, C₆F₁₃C₆H₄CH[O(C₂H₄O)_mH]C₅H₁₁ (F6PH5EOm: m = 4, 8, 10, 14, C₆H₄ = p-phenylene), were synthesized. The surfactants synthesized were found to be as stable and hardly hydrolyzable as the previously reported ionic hybrid surfactants. F6PH5EO10 and F6PH5EO14 were highly surface-active and water-soluble while their critical micelle concentrations (cmc) determined by surface tension measurements were low compared with those of sulfate-type hybrid surfactants, C₆F₁₃C₆H₄CH(OSO₃Na)C₅H₁₁ (F6PH5OS, C₆H₄ = p-phenylene), and phosphate-type hybrid surfactants, C₆F₁₃C₆H₄CH[OPO₂(OC₆H₅)Na]C₅H₁₁ (F6PH5PPhNa, C₆H₄ = p-phenylene, C₆H₅ = phenyl), both of which also have a benzene ring as a spacer. The cloud point of F6PH5EO14 in solutions of salts such as NaCl and CaCl₂ decreased with increasing salt concentration and the decreasing rate was the largest for NaCl, whereas the surfactant showed solubility high enough for use in physiological saline solution at temperatures around the body temperature.