Recent advances in cathodic electrodeposition coatings with special reference to resin materials: A comprehensive review

Coatings are of utmost importance in the modern technology-based world. Protective polymer coatings have become a crucial part of a variety of industries, including automobiles, electronics, infrastructure, and medical industries in order to enhance the lifetime of the products. Cathodic electrodeposition (CED) coatings provide a groundbreaking technology that offers a major advantage over other traditional coating methods by limiting the use of solvent-based resins and replacing it with water-based resins like acrylic, epoxy, epoxy-acrylate and polyurethane resins. CED coating requires specially modified resins that can be made electrophoretic and deposited on the cathodic materials. CED coatings minimizes the emission of volatile organic compounds and the coating obtained has better corrosion protection, adhesion to metals, ability to coat irregular surfaces and intricate designs. Despite such myriad of advantages, there are few efforts have been made to review the process parameters and the current development and tailoring of resins for CED coatings. Therefore, this review aims to create an inventory for the state-of-the-art advances that have taken place in the light of CED coatings. To provide a strong basis for understanding of the process and the history are discussed in the initial parts. The main highlight of the review is the advancement in the resin materials for CED coatings. Special emphasis has been given to acrylic, epoxy, polyurethane and epoxy-acrylate resins, their synthesis, coating process and their modifications to tailor the coating properties for advanced applications. The later sections also discuss about the strategies and parameters for improving the coating performance both in terms of the resin development as well as coating process. We hope this review will serve as a one-stop resource for any research working in CED coatings and also help them to device new research ideas with the challenges and the future prospects discussed in the final section of the paper.