Abstract: A gemini imidazoline derivative anti-rust additive was prepared from oil acid and triethylenetetramine, and the synthesis conditions were optimized by response surface method. The performance of synthetic anti-rust additive was investigated by liquid corrosion test (synthetic seawater), hygrothermal test, emulsion resistance test, sludge test and corrosion tendency test. The optimum synthesis conditions were as follows:a molar ratio of triethylenetetramine to oil acid of 0.63:1, a reaction temperature of 248 ℃, and a reaction time of 7.9 h. The yield of gemini imidazoline derivative was 90%. The results of performance evaluation showed that gemini imidazoline derivatives could significantly improve the anti-rust performance of API I lube base oil, but had poor sensitivity to API II and API III base oil. In API class I base oil, the antirust performance of gemini imidazoline derivatives was equivalent to T705A and better than T746, T703, RHY702 and other rust inhibitors. When gemini imidazoline derivatives were used in the formulation of steam turbine oil, the steam turbine oil with different viscosity grades and properties meeting the quality requirements of Q/SY RH2087-2012 standard could be obtained.

Key words: gemini imidazoline derivative, lubricating oil, anti-rust additive, response surface method