Corrosion Inhibition Performance of Waterborne Acrylic Copolymer Nanoparticles: Experimental and Theoretical Insights into Copolymer Composition

The development of waterborne corrosion inhibitors has emerged as a promising strategy for mitigating the degradation of metallic materials in aggressive media while reducing the use of volatile organic solvents. In this context, acrylic copolymers synthesized via miniemulsion polymerization have demonstrated notable corrosion inhibition performance in various corrosive environments, including HCl, H₂SO₄, and NaCl solutions. In the present study, methyl methacrylate–butyl acrylate (MMA-co-BuA) copolymers with varying monomer composition were synthesized, and their corrosion inhibition behavior toward mild steel in 1 M HCl was systematically investigated. Electrochemical techniques, namely potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), were employed to evaluate the inhibition performance. The thermal stability and particle size distribution of the synthesized copolymers were examined using thermogravimetric analysis (TGA) and dynamic light scattering (DLS), respectively. Furthermore, the molecular structures, electronic properties, and reactivity of the copolymers were analyzed using quantum-chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) simulations. The results indicate that increasing the MMA content enhances the corrosion inhibition performance of the MMA-co-BuA copolymer. This behavior may be related to variations in copolymer polarity and interfacial interactions, which could influence the adsorption process at the metal/electrolyte interface. Notably, at an MMA: BuA ratio of 80:20 and an inhibitor concentration of 40 ppm, a maximum inhibition efficiency of 82.7% was achieved. This enhanced performance may be associated with changes in copolymer polarity and interfacial interactions resulting from the increased MMA content, thereby promoting the formation of a more effective protective layer on the steel surface.