Synthesis and application of idesia oil-based imidazoline derivative as an effective corrosion inhibitor for Q235 steel in hydrochloric acid medium†

Idesia oil-based imidazoline derivative (IOID) as a corrosion inhibitor was synthesized through the solvent dehydration method for Q235 steel in HCl solution. It was characterized by FTIR, and the corrosion inhibition performance was evaluated by static weight loss testing and electrochemical measurements. The corrosion inhibition mechanism of IOID was also investigated. The results indicated that the optimized synthetic method for IOID involved a 1 : 1 molar ratio of imidazoline intermediate to quaternization reagent, under a quaternization reaction temperature of 80 °C and a quaternization reaction time of 2 h. The inhibition efficiency of over 99.07% was achievable when 40 ppm IOID was applied in 1 M HCl solution at 80 °C, even after the inhibitor was used for one week. The corrosion inhibition mechanism involved the corrosion products covering the steel substrate surface and forming a dense protective film. Physical adsorption occurred on the steel substrate surface, which played a protective role for Q235 steel.