Synthesis and Properties of Quaternary Ammonium Imidazoline Gemini Surfactants

Quaternary ammonium imidazoline Gemini surfactant was synthesized by using epichlorohydrin as coupling agent,oleic acid as hydrophobic chain,diethylenetriamine as hydrophilic chain,and the structure of Gemini surfactant was characterized by IR and 1HNMR.Emulsifying power for benzene,foam stability,HLB,aqueous solution surface tension of the Gemini surfactant was investigated.Dynamic laser light scattering method was utilized to characterize the particle size distribution of O/W emulsion,in which oleic acid was the dispersed phase using Gemini surfactant as emulsifier.Static weight loss method was adopted to evaluate the corrosion inhibition performance of Gemini surfactant as corrosion inhibitors for Q235 steel in mass fraction 8% HCl.The results show that the critical micelle concentration of Gemini surfactant was 2×10-4 mol/L,γCMC was 31.40 mN/m,HLB was 14.2,the quaternary ammonium Gemini surfactants exhibited good surface activity,steady foam power and excellent emulsifying performance against benzene.The results of particle size distribution indicate that the latex particle dimension of O/W emulsion is between 216～236 nm,with narrow distribution at emulsifying temperatures of 25～50 ℃,and the quaternary ammonium imidazolines Gemini surfactant is an O/W emulsifier of good performance.The static weight loss tests show that the inhibition efficiency of quaternary ammonium imidazolines Gemini surfactant is superior to that of the corresponding single-chain quaternary ammonium imidazolines surfactant.