Physicochemical parameters influencing the testing of cathodic delamination resistance of high build pigmented epoxy coating
By Subrahmanya Shreepathi
Published in Progress in Organic Coatings
2016
Abstract
Cathodic protection, a widely used corrosion mitigation method, is generally achieved either by using sacrificial anodes or by applying external impressed current. However, under applied cathodic potential, organic coatings disbond from the substrate. Performance of a protective coating hence is evaluated by cathodic disbondment test. A higher cathodic disbonding resistance of the coating implies a better performance. There are two types of parameters which strongly influence the cathodic disbonding resistance of organic coatings. The first ones are physicochemical parameters such as applied cathodic potential, coating thickness, electrolyte, test temperature, time, etc. The second type of parameter is purely attributed to coating composition. In the present study, external factors such as temperature, applied cathodic potential and chemical composition of the electrolyte influencing the cathodic disbonding rate of organic coating are studied in detail. In addition, electrochemical impedance spectroscopy was used to evaluate the anticorrosive properties and study the influence of applied cathodic potential on barrier property of these coatings.