Mercaptopropionic acid-modified oleic imidazoline as a highly efficient corrosion inhibitor for carbon steel in CO2-saturated formation water

Two imidazoline derivatives (OI and MOI) were synthesized as highly efficient inhibitors, and their inhibition performances and mechanisms in CO2-containing solution were studied using weight loss measurements, elec-trochemical tests, surface analysis and theoretical calculations. The results indicate that OI and MOI show excellent inhibition efficiency. Especially for MOI, its inhibition efficiency is as high as 95.58% at 20 ppm. Theoretical calculations confirm that both inhibitors successfully adsorb on metal surface via chemisorption. MOI shows a better inhibition performance than OI, because the sulfhydryl in MOI can be used as a powerful adsorption site, effectively improving the adsorption ability of MOI.