Abstract
Abstract
Background
Chicken feather waste is a protein-rich biomass that can be converted into keratin-based materials with potential applications in corrosion protection. This study evaluated a keratin-based bioplastic (KBP) prepared from waste chicken feathers as a corrosion inhibitor for mild steel in 0.1 M hydrochloric acid.
Methods
Keratin was obtained by alkaline hydrolysis followed by acid precipitation and incorporated with glycerol and microcrystalline cellulose to form a bioplastic film. The material was characterized using FTIR, SEM, EDX, XRD and DSC. Corrosion behaviour was assessed by gravimetric and electrochemical methods over 303–333 K and at KBP concentrations of 0–0.8 g/L for the temperature-dependent electrochemical dataset. Potentiodynamic polarization was performed in a three-electrode cell after 30 min open-circuit stabilization. Adsorption behavior was evaluated using Langmuir, Freundlich and Temkin models.
Results
Increasing KBP concentration reduced corrosion current density and corrosion rate while increasing polarization resistance, surface coverage and inhibition efficiency. At 303 K, corrosion rate decreased from 37.56 mm year⁻¹ in the uninhibited system to 21.79 mm year⁻¹ at 0.8 g/L, corresponding to 41.99% inhibition efficiency. Polarization data indicated mixed type inhibition behavior while the highest inhibition efficiency in the temperature series was 54.00% at 0.8 g/L and 323 K, after which efficiency declined to 32.49% at 333 K. The Langmuir model showed the highest linear-fit coefficients (R² = 0.9994–0.9997) among the evaluated models, although the high fits of the other models indicate that model fit alone does not establish a unique adsorption mechanism. Activation energies increased from 15.26 kJ mol⁻¹ in the uninhibited system to 17.80 kJ mol⁻¹ at 0.8 g/L KBP.
Conclusion
The chicken feather-derived KBP reduced mild-steel corrosion under the tested acidic conditions, with performance dependent on concentration and temperature. The results are consistent with adsorption-mediated inhibition and surface modification. The adsorption and thermodynamic results should be interpreted as mechanistic evidence rather than definitive proof of a single adsorption mode.