Corrosion inhibition performance of poly (N-(2-phenylhydrazine-1-carbonothioyl) Acrylamide/Acrylic Acid) (NPCA/AAc) for 304 stainless steel and 1070 aluminum alloy in chloride media

Corrosion in aggressive chloride environments presents significant obstacles to the structural integrity and durability of metals such as 304 stainless steel (SS) and 1070 aluminum (Al) alloy, widely used in industrial applications. This study investigates the corrosion inhibition efficiency of a novel inhibitor, N-(2-phenylhydrazine-1-carbonothioyl) acrylamide/polyacrylic acid poly(NPCA/AAc), which combines the adsorption capabilities of secondary amines, thioamide, and carboxylic acid groups with the film-forming properties of polyacrylic acid. Electrochemical techniques were used to evaluate corrosion inhibition performance, and surface morphology was analyzed using scanning electron microscopy (SEM) to assess the extent of surface protection. The optimum results were achieved with 0.05 mg/L Poly(NPCA/AAc), which significantly reduced corrosion current density (I_corr) for 304 SS (from 14.4809 to 9.5908 µA/cm²) and 1070 Al (from 8.33744 to 0.6735 µA/cm²). Charge transfer resistance (R_ct) increased for both alloys, indicating the formation of a stable protective film. SEM analysis confirmed smoother and more uniform surfaces, demonstrating the inhibitor’s ability to mitigate both uniform and localized corrosion. In conclusion, Poly(NPCA/AAc) exhibited mixed-type inhibition behavior, effectively reducing anodic dissolution and cathodic hydrogen evolution. Its dual effectiveness on ferrous and non-ferrous alloys highlights its potential as a versatile, eco-friendly corrosion inhibitor for industrial applications in aggressive chloride environments.