Conducting polymers for corrosion protection: a review

Abstract

Since the first reported publications about their possible application for corrosion protection, conducting polymers are discussed as promising candidates for a new generation of corrosion control coatings. However, although research has started about three decades ago and certainly about a thousand publications have been published on this topic, their technical application has not yet made its breakthrough.The reason for this is that most coatings based on conducting polymers fail so far under practical corrosion conditions. Reasons will be discussed in this paper, as well as future challenges. As will be shown, conducting redox polymers such as polypyrrole or polyaniline indeed posses a promising potential for intelligent corrosion protection, but up to now this potential has not been explored.

Novel conducting polymer based composite coatings for corrosion protection of zinc

“…However, despite of all positive reports on CPs for corrosion protection, their application is not without problems [15][16][17]. Continuous coatings of conducting polymer may disastrously fail in the presence of a larger defect and may even cause an enhancement of corrosive attack [15].…”

“…Continuous coatings of conducting polymer may disastrously fail in the presence of a larger defect and may even cause an enhancement of corrosive attack [15]. Only when used as additives in composite coatings a safe use will be possible [15] provided that they promote the formation of a passive metal surface at the coating/ metal interface [17][18][19]. Another problem is that CPs applied on zinc lead to the formation of an insulating layer at CP/metal interface resulting in electronically decoupling (Fermi-level misalignment) between the CP and the metal, leading to a seemingly too low potential.…”

Recent Approaches for Designing Nanomaterials-Based Coatings for Corrosion Protection

“…ECPs are known for their ability to undergo oxidation-reduction reactions by gaining or loosing electrons from the surrounding environment. Due to this interesting property, ECPs have been utilized as novel corrosion-protective coatings for a variety of metals and alloys [92][93][94].…”

“SURFACE and INTERFACE ENGINEERING”

“…Whereas MCrAlY coatings have already found successful application in practice (since, say, 2000), coatings of conducting polymers, which are promising for application to steels for corrosion protection, are still under development (after thirty years) and have not found wide practical application until now. An overview of the current state of knowledge, the problems facing the materials scientist in this area and possible remedies are dealt with in the paper by Rohwerder [4].…”