Polymers in Corrosion Prevention and Control

Berry, B.C., A.U. Shaikh, and T. Viswanathan. 2003. Lignosulfonic acid-doped polyaniline (ligno-pani) for the corrosion prevention of cold-rolled steel. In Electroactive polymers for corrosion control, eds. P. Zarras, J.D. Stenger-Smith, and Y. Wei, 182. Washington DC American Chemical Society. 

Corrosion is the deterioration of a material by reaction with its enviromnent. Although the term is used primarily in conjunction with the deterioration of metals, the broader definition allows it to be used in conjunction with all types of materials. We will limit the description to corrosion of metals and alloys for the moment and will save the degradation of other types of materials, such as polymers, for a later section. In this section, we will see how corrosion is perhaps the clearest example of the battle between thermodynamics and kinetics for determining the likelihood of a given reaction occurring within a specified time period. We will also see how important this process is from an industrial standpoint. For example, a 1995 study showed that metallic corrosion costs the U.S. economy about 300 billion each year and that 30% of this cost could be prevented by using modem corrosion control techniques [9], It is important to understand the mechanisms of corrosion before we can attempt to control it. 

Leidheiser 9l) has proposed numerous methods of attack which can be used in an attempt to prevent or minimize the corrosion-induced delamination of polymer coatings from metal substrates. All of these methods involve the control of the chemical and physical properties of the interfacial layer between the coating and the metal substrate. Three of these methods are discussed in Sections 6.3.3-6.3.5. 

Programs such as phosphate and zinc treatments of boiler and cooling water require the use of appropriate polymer to demonstrate satisfactory corrosion control. These polymers also prevent bulk precipitation of the corrosion additives in the circulating water. Sulfonated copolymers have thus proven to be effective for both boiler and cooling water treatments. 

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