Abstract: A novel diester type cationic surfactant was prepared with waste oil collected from trench-sewer as raw material via chemical processes as hydrolysis,open-ring esterification with epichlorohydrin,esterification with oleic acid,and quaternization.FT-IR was used to characterize the chemical groups of the product.Moreover,the critical micelle concentration of the product was determined by surface tension method and electrical conductivity method.Finally,the degradation behavior of the cationic surfactant product was examined by aerobic sludge method.

Key words: cationic surfactant, waste oil, oleic acid, diester, surface activity