Scientists have examined the coating delamination mitigation by inhibiting the hydrogen evolution reaction.
The mitigation of coating delamination is one of the important challenges for epoxy coatings under the cathodic protection. Scientists report the possibility to mitigate the coating delamination of epoxy coatings by inhibiting the hydrogen evolution reaction in the presence of thioureas. The wire beam electrode method, electrochemical impedance spectroscopy and traditional delamination test were employed to evaluate the mitigation efficiency in the work.
Results show that in the absence of thioureas, the delamination rate increases significantly once the cathodic protection potential is more negative than hydrogen evolution potential, suggesting that hydrogen evolution reaction plays an important role in the coating delamination. Fortunately, the coating delamination is remarkably mitigated by adding thioureas since the hydrogen evolution reaction is suppressed.