Abstract: A series of sodium hexyl and octyl succinic acid ester sulfonate (SS) and a series of sodium bis-hexyl and bis-octyl Gemini succinic acid ester sulfonate (GSS) were synthesized.The relationship between the performances,such as permeability,emulsification,resistance to hard water and the critical micelle concentration,and the branching degree of the hydrophobic chain were mainly investigated.Results showed that,for the series of hexyl SS and hexyl GSS,the changing tendency of the emulsification and the resistance to hard water are same as the change of branching degree of the hydrophobic chain.When the spacer length is less than the equilibrium separation of the hydrophilic groups,trends of change of the critical micelle concentration of the hexyl GSS and the SS are same with the branching degree of the hydrophobic chain,and when the spacer length is longer than the equilibrium separation,the changing tendency is on the contrary.As the change of the branching degree of the hydrophobic chain of the octyl SS and octyl GSS,change of the resistance to hard water and the critical micelle concentration is in same direction,while the permeability changes contrarily.The emulsification changes differently.

Key words: anionic surfactant, sodium sulfosuccinate, property