Determination of the adhesion properties of an alkyd pigmented coating by electrochemical impedance spectroscopy

One of the most modern methods of characterizing the electrical properties of coatings is by electrochemical impedance spectroscopy (ELS). EIS can pro vide useful information about the transport of water and corrosive species through a coating. In this study, impedance measurements were performed in different frequency ranges at open circuit potential for an alkyd coating w ith TiO2 as a mineral pigment in 3% NaCl. The most probable impedance equiv alent circuit method (MPI) was considered for data analysis. The interpreta tion of the impedance spectra permitted the determination of water permeati on, the formation of blisters, swelling of the coating, and the loss of adh esion.