Non-destructive tests on eco-friendly anti-corrosion paint

Abstract

Henna is identified as an excellent corrosion inhibitor and due to this reason, a research project was conducted in order to investigate the ability of henna extracts to act as an anticorrosive agent with the compatible composition for paint systems. The paint composition consisted of colophony (WW types), plasticiser (oleic acid), pigment (calcium carbonate), solvent (mixture of xylene/white spirit) and additives (zinc oxide and henna leaf extract). These ingredients were mixed until they were soluble and stirred using a high-speed disperser. In order to measure the effectiveness of the new paint system, several nondestructive tests were conducted to investigate the inhibitive properties of henna extract including measurement of substrate mass loss. The inhibition efficiency (IE) increased with the increasing amounts of inhibitor. The highest IE (%) was 77.63% and this was produced by the paint with 8% inhibitor (P3). However, the IE value started to decrease when 12% of henna extract was incorporated into the paint matrix (P4: 58.40%). Thus, P3 acted as an optimum paint with respect to its performance on the corrosion inhibition efficiency based on mass loss measurement and electrochemical studies. Surface analyses were carried out using infrared thermography and scanning electron microscopy. These surface analysis test was carried out to support mass loss and electrochemical study. Based on the results, the performance of henna extract as a corrosion inhibitor on aluminium surface showed a great impact with the 8% of henna extract presence in the paint formulation.

Keywords

• corrosion
• ir thermography
• non-destructive testing