Abstract: Surface activity of cardanol polyoxyethylene ether BGF-10 and the effects of different additives on the surface activity were studied.Results show that the critical micelle concentration (cmc) of BGF-10 is 6.09×10^-6 mol/L,and the lowest surface tension (γ_cmc) is 38.08 mN/m at 25 ℃.Moreover,BGF-10 displays a better resistance to hard water and a strong salt tolerance to monovalent inorganic salts.With the increase of concentration of divalent inorganic salt,the surface activity of BGF-10 is enhanced.Monohydric alcohol can reduce the surface tension of BGF-10.The ability of BGF-10 to form micelles increases in the beginning and then decreases with the increase of monohydric alcohol concentration.BGF-10 displays a synergistic effect with other surfactants,especially with hexadecyltrimethylammonium bromide (CTAB),and its cmc synergizes upto 2.52%,while the γ_cmc synergizes upto 11.49%.BGF-10 displays a good emulsifying power for paraffin oil,as well as both thickening and defoaming performance.

Key words: cardanol polyoxyethylene ether, critical micelle concentration, surface tension, blending