IMPEDANCE STUDY OF THE CORROSION PROTECTION PROPERTIES OF FLUOROPOLYMER COATINGS

Fluoropolymers have attained great importance as coating materials bec ause of their excellent resistance to high temperature, to chemicals a nd to organic solvents. Electrochemical impedance spectroscopy has bee n used to study the corrosion protection properties both of undamaged fluoropolymer coatings and of samples with an artificial defect. The e xperimental results have been interpreted on the basis of a proposed e quivalent electrical circuit which best fits the experimental impedanc e spectra. In this way, the high performance of fluorinated coatings c ompared to the corresponding hydrogenated polymer as a reference has b een 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 t he resins.