Development of anti-corrosive paint incorporated with henna extract as a natural inhibitor

Abstract

Metallic materials are the most applicable materials in various industries. They are useful due to their excellent mechanical properties. However, they are exposed to corrosion because the environment contains oxygen, humidity and some other factors. This paper describes about a paint incorporated with organic inhibitor, i.e., henna extract. This paint was produced to enhance its anticorrosive property. Henna extract was chosen as the corrosion inhibitor as it is organic, environmentally acceptable, readily available and a renewable source of material for a wide range of corrosion problems. The extractions were characterised by using Fourier Transform Infrared. Meanwhile, the inhibitive action of henna extract was investigated through an electrochemical technique. The inhibitive effects of henna extract were investigated with percentages of 0%, 4%, 8% and 10% incorporated into a rosin (epoxy)-based matrix. The specimens were characterised by electrochemical impedance spectroscopy measurement. The morphology study was investigated through surface analysis by using scanning electron microscopy. The inhibition efficiency increased as the concentration of henna extract was increased. The results showed that Paint 3 has the lowest corrosion rate of 0.001767 mm/yr as compared to Paint 1 with 0.005148 mm/yr. The inhibitive action of the henna extract is discussed. Paint 3 was proposed as the most effective paint that contains a natural inhibitor for aluminium alloy.