IMPEDANCE STUDY OF THE CORROSION PROTECTION PROPERTIES OF FLUOROPOLYMER COATINGS

Fluoropolymers have attained great importance as coating materials because of their excellent resistance to high temperature, to chemicals and to organic solvents. Electrochemical impedance spectroscopy has been used to study the corrosion protection properties both of undamaged fluoropolymer coatings and of samples with an artificial defect. The experimental results have been interpreted on the basis of a proposed equivalent electrical circuit which best fits the experimental impedance spectra. In this way, the high performance of fluorinated coatings compared to the corresponding hydrogenated polymer as a reference has been observed. The protective properties of fluoropolymer coatings can be related to the chemical (fluorine and chlorine function groups) and physical (high ordering of the polymeric chains) characteristics of the resins.