Abstract: Three kinds of Bolaform asymmetrical cationic surfactant were synthesized through two step reaction with α,ω-dibromo alkane,n-butyl imidazole and tributylphosphine as starting materials.Optimized conditions for preparation of the intermediate 1-(12-bromo-dodecyl)-3-butylimidazolium bromide are:n(n-butyl imidazole):n(1,12-dibromo-dodecane):n(tetrabutylammonium iodide)=1:1.5:0.005;at 65 ℃ for 6 h with isopropanol as solvent.Conditions for preparation of the product are:n(1-(12-bromo-dodecyl)-3-butylimidazolium bromide):n(tributylphosphine)=1.05:1;at 80 ℃ for 12 h with assistance of microwave irradiation.The synthesized products display good surface active performance.Their cmc is 5.7×10^-3~8.7×10^-2 mol·L^-1;γ_cmc is 30~36 mN·m^-1 at 30 ℃.With increasing of the carbon chain length,their cmc,γ_cmc and A_min decreases,while Γ_max and pc₂₀ increases.

Key words: Bolaform surfactant, cationic, imidazole, tributylphosphine, microwave irradiation