Anticorrosive coatings protective mechanisms

Winding of the outer layer protecting the anticorrosion insulation against mechanical damage during transportation and installation of the pipeline. This layer is made of a sufficiently thick PE film (0.5 mm), which is the adhesive coat carrier. 

An advantage of incorporating ECPs into a binder such as epoxy or polyurethane is the good adhesion that such binders provide, and the actual performance of coatings based on formulation may be due to the fact that the adhesion is better than that obtained by electropolymerization. However, this strategy leads to less contact between metal and ECP and, in view of the protection mechanisms described in Section 16.2, this may be to the detriment of the anticorrosion properties. 

Anticorrosive coatings are generally classified according to the mechanisms by which they protect a metal against corrosion. The three basic protective mechanisms of anticorrosive coatings are as follows ... 

One of the reasons for local corrosion at the metal-polymer interface is sorption of electrolytes by polymers and permeability of the polymer barrier towards electrolytes. Sorption of electrolytes (acid solutions, bases and salts) leads to essential variation in the service characteristics of the protecting polymer coatings and anticorrosion packaging films under mechanical loads. These variations under mechanical loads, especially in seals and friction joints, are much deeper and can affect mechanisms of contact interactions. 

---