Abstract

The pickling process conducted in acidic environments presents notable environmental concerns, largely attributed to the utilization of synthetic organic compounds as corrosion inhibitors for the protection of carbon steel surfaces. To mitigate these environmental impacts and suppress corrosion rates, the advancement of eco-friendly, naturally derived inhibitors has garnered increasing attention. In the present work, an extract obtained from Ceiba pentandra (kapok) leaves was investigated as a potential corrosion inhibitor for carbon steel in 1 M HCl solution. The inhibitory behavior was examined using Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) at varying extract concentrations. Findings revealed that the kapok leaf extract developed a dense and uniform protective layer on the steel surface, effectively diminishing the corrosion rate. At the optimum concentration of 3000 mg/L, the inhibition efficiency achieved 80.31%. EIS measurements further indicated a pronounced enhancement in polarization resistance, confirming the establishment of a stable inhibitor film. These results highlight that kapok leaf extract exhibits considerable potential as a green and sustainable corrosion inhibitor in acidic conditions, offering a promising alternative to conventional synthetic inhibitors for industrial applications.