Influence of inhibitors on the resistance of polymeric corrosion-inhibiting coatings to cathodic delamination

An annular cut in a coating of given radius and width is used instead of a continuous circular cut for the assessment of the resistance to cathodic delamination. To compare the efficiency, we make both cuts on the same specimen, paste two transparent cylinders in line with the cuts, fill them with a 3% aqueous solution of sodium chloride, and set up platinum electrodes and connect them in parallel to one voltage source. We investigate two types of coatings: polyurethane–perchlorovinyl and organosilicon ones. It is established that, using annular cuts, more exact information on the resistance to cathodic delamination of the coatings can be obtained.