Microbial Corrosion of Protective Coatings

Abstract

Research studies have shown that protective coatings of diverse chemical composition represent a powerful factor stimulating the bacterial activity of corrosion inducers. On the film and mastic coatings investigated in the present paper, bacterial communities are formed, which consist of bacteria of various ecological trophic groups. Bacteria in a biofilm are characterised by high metabolic activity and the ability to destroy traditional coatings. As a result of microbial destruction, the physical mechanical and chemical properties of a material undergo significant changes. The characteristics of strength, elasticity and adhesion deteriorate, thus degrading the main function of the coatings, i.e.protection of metal against corrosion. An efficient method of protection against biodeterioration is the addition of corrosion inhibitors with biocide action into their composition. It was established that the population of bacteria on oil bitumen coatings modified by antimicrobial bonds is 1–4 orders lower than on materials with no such additives. Protection of underground structures against corrosion should be performed comprehensively with consideration of the biocorrosivity of soils and bioresistance of coatings.

The dual role of microbes in corrosion

“…This can be achieved by the application of protective coatings or either anodic or cathodic protection. However, many coatings have been shown to be subject to microbial degradation (Kopteva et al, 2004). Coatings with added antimicrobials were shown to inhibit microbial degradation (Gottenbos et al, 2002;Park et al, 2004), for example, silver-based coatings were effective in the inhibition of biofilm formation (Liedberg and Lundeberg, 1989).…”

Polymers for Combating Biocorrosion

“…Moisture beneath a poorly bonded coating may contain microbial contaminants, and conditions are favorable for anaerobic growth (Videla, 1996), (iii) polymer coatings readily suffer from microbiologically induced degradation, since some microorganisms can use the coating films as a nutrient source by their physiological activities on the coating surface, thus resulting in the loss of protection capacity of coatings. Furthermore, the corrosive biodegradation products have been found detrimental to the biofilm-attached metals (Flemming, 1998;Kopteva et al, 2004). To circumvent the problem of microbial degradation, the biocidal functionality has been conferred to the polymer coatings to inhibit the attachment of bacterial cells and subsequent formation in recent years (Crum et al, 1967;Sugama, 1995;Sugama and DuVall, 1996;Thomas et al, 2004;Ananda Kumar et al, 2006;Choi et al, 2007;Yuan et al, 2007Yuan et al, , 2009aYuan et al, ,b,c, 2010aLebrini et al, 2008;Stobie et al, 2009;Videla and Herrera, 2009;Wan et al, 2009;Zafar et al, 2009;Yang et al, 2014;Grover et al, 2016;Yesudass et al, 2017).…”

Hexagonal Boron Nitride for Sulfur Corrosion Inhibition

“…Biotic corrosion, commonly termed as microbiologically influenced corrosion (MIC), turns harmless sulfates into aggressive sulfides to degrade copper components of pipelines, transformers, printed circuit boards, and mechanical equipment, all under ambient conditions. Sulfur corrosion is typically controlled by introducing a protective coating layer of polymers such as VOC alkyd, silicone alkyd, polyurethane, latex, epoxy, and polyamides . However, their porous structure renders them susceptible to hydrolysis, degradation, and biogenic sulfide attack.…”

“…Sulfur corrosion is typically controlled by introducing a protective coating layer of polymers such as VOC alkyd, silicone alkyd, polyurethane, latex, epoxy, and polyamides. 5 However, their porous structure renders them susceptible to hydrolysis, degradation, and biogenic sulfide attack. The substantial thickness of polymer coatings may also disrupt the functionality of the underlying metals.…”