The Preparation of a Novel Corrosion Inhibitor and Its Corrosion Inhibition Behavior on 2024 Al-Cu-Mg Alloy in Acid Solution

A new corrosion inhibitor was synthesized from chloroacetyl chloride, 1,3-propanediamine, and dodecyldimethyl tertiary amine. The structure of the synthesized product was characterized using Fourier transform infrared(FTIR). The critical micelle concentration (CMC) was determined from surface tension measurements. The inhibition behavior of the corrosion inhibitor for 2024 Al-Cu-Mg alloy was studied using the weight-loss method and electrochemical measurements in hydrochloric acid solution. Experimental results show: The CMC is 7.767 × 10⁻⁴ mol L⁻¹ and IE (C _pro = 1 × 10⁻³ mol L⁻¹) ≈ 87.9%. The adsorption free energy is calculated to be −33.12 kJ mol⁻¹. Therefore, the adsorption mode is more inclined to physical adsorption. When the concentration of the synthesized product is lower than the CMC, it satisfies the Langmuir adsorption model; when the concentration is higher than the CMC, it no longer follows the Langmuir adsorption model.