Development and performance evaluation of bio-based polymeric composites as multi-environment corrosion inhibitors for industrial alloys

This study aimed to synthesize, characterize, and evaluate the corrosion inhibition performance of two novel compounds: an Arabic gum–abietic acid complex (Compound 1) and a polyvinylpyrrolidone–dextran complex (Compound 2) for protecting brass (Cu–Zn), bronze (Cu–Al–Ni–Fe), and 304 stainless steels in rainwater, seawater, and artificial sweat environments. The research employed a multi-analytical approach combining potentiodynamic polarization, gravimetric analysis, and surface characterization techniques (scanning electron microscopy/energy-dispersive X-ray spectroscopy). Inhibitor compounds were synthesized through controlled solution mixing and cross-linking processes. Corrosion studies were conducted across three different environments with exposure periods of 10 days. Key challenges included maintaining inhibitor stability across different pH levels, ensuring uniform surface coverage on diverse alloy compositions, and achieving consistent protection in environments with varying ionic strengths and aggressive species. Results demonstrated that Compound 1 consistently outperformed Compound 2 across all tested conditions, with the highest inhibition efficiency observed for the Cu–Al–Ni–Fe alloy. Compound 1 achieved inhibition efficiencies of 55.6%, 66.9%, and 26.7% in rainwater for brass, bronze, and stainless steel, respectively. In sweat solution, the efficiencies were significantly higher, reaching 57.8% for brass, 89.4% for bronze, and 32.8% for stainless steel. These findings highlight the superior performance of Compound 1, particularly in chloride-rich environments such as sweat solution.