Eggshells biowaste filler for improving the anticorrosive behaviour of waterborne polyurethane coatings on mild steel in artificial seawater

Abstract

The efficacy of eggshells (ES) powders as an anticorrosive pigment with TiO2 nanoparticles in waterborne polyurethane coatings has been investigated. The experiment was conducted on mild steel in a corrosive solution of artificial seawater. Several characterizations to analyze the effects of ES addition were performed, including the classical weight loss method, water contact angle, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and scanning electron microscopy with energy dispersive X-ray (SEM/EDX). The addition of ES powders was determined to increase the coating's protection efficiency until 20 wt% (P4). Furthermore, based on the morphological study, it was discovered that the best concentration managed to maintain the surface integrity of the coatings with no defects were detected even after 20 days of exposure.

Keywords

• Corrosion
• Eggshells
• Waterborne polyurethane
• Mild steel
• Seawater