CITRUS AURANTIFOLIA LEAF EXTRACT AS A POTENTIAL ANTI-CORROSION ADDITIVE IN ALKYD PAINT FOR MILD STEEL

Abstract

Citrus aurantifolia leaf extract (CAL) has been used as an anti-corrosion additive in alkyd paint and tested in 0.2M HCl. Fourier transform infrared (FTIR) spectroscopy showed several active functional groups and the occurrence of complexation between alkyd paint and CAL extract. Corrosion assessment of the newly modified paint was conducted by weight-loss measurements, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Weight-loss percentage was found to decrease as the concentration of CAL extract increased for each week, whereas the effect of the immersion period shows an inverse trend for each concentration. In addition, the Nyquist plot exhibited an increase in the diameter of the semicircle as CAL extract concentrations increased, indicating the coating's resistance towards corrosion. A morphological analysis study using a scanning electron microscope (SEM) confirmed cross-linking between CAL extract and alkyd resin, while several coating defects were observed. Hence CAL extract shows an acceptable potential as anti-corrosion additive in alkyd paint for acidic medium application.