Inhibition properties and adsorption behavior of imidazole and 2-phenyl-2-imidazoline on AA5052 in 1.0 M HCl solution

• IM and 2-PI show corrosion inhibition for AA5052 in HCl solution.
• Synergistic effect between IM and 2-PI is observed and its mechanism is assumed.
• Adsorption properties are estimated using ΔGads0, ΔHads0 and Ea, respectively.
• Adsorption structures and inhibition mechanism for AA5052 are proposed.

The inhibition behavior of imidazole (IM) and 2-phenyl-2-imidazoline (2-PI) for AA5052 was investigated by weight loss, electrochemical, contact angle measurements and scanning electron microscopy. The results show that IM and 2-PI can inhibit the corrosion of AA5052 and the inhibition efficiency of 2-PI is higher. The adsorption properties of them are estimated using ΔGads0, ΔHads0 and Ea. The results reveal that the adsorption processes are exothermic reactions mainly by a monolayer chemisorption mechanism, and follow Langmuir adsorption isotherm. The differences of the monolayer adsorption structure between IM and 2-PI on AA5052 surface are analyzed, and the inhibition mechanisms are proposed.