Abstract: A new sulfodehydroabietic acid based bis-quaternary ammonium cationic surfactant (Ⅲ) was synthesized by sulfonation of dehydroabietic acid, followed by reaction with epoxypropyl triethyl ammonium chloride. Structures of products were characterized by IR.Surface activities of Ⅲ and the mixed system of sodium dodecyl sulphate (SDS) with Ⅲ were determined. Results show that content of sulfodehydroabietic acid is 92% by weight and content of cationic surface active substance is 91%. Critical micelle concentration (CMC) of Ⅲ is 1.1 mmol/L, and the foaming ability is 12 mm, showing a strong emulsification ability. Strong synergism of Ⅲ with SDS is observed, and the optimum synergism is obtained at the mass ratio of 1:3.

Key words: dehydroabietic acid, epichlorohydrin, bis-quaternary ammonium cationic surfactant