Corrosion Resistance of Clay Modified Resole and Novolac Phenolic Coatings

In this study corrosion resistance and adhesion properties of two types of phenolic coatings, novolac and resol, have been investigated. Phenolic coatings containing clay particles were prepared and the effect of clay content on the corrosion protection performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS), DC polarization and salt fog tests. On the other hand, adhesion and toughness characterization of prepared phenolic coatings was measured using pull off and cupping tests, respectively. Results indicated that adding of clay particles, improves the corrosion protection performance both of both types of phenolic coatings. Novolac phenolic coating containing 3 wt % of clay showed higher corrosion resistance than the others. Also, test results showed that the flexibility and adhesion of resol coating was more than that of the novolac coating.