Evaluation on Protective Performance of Organic Coatings by Analyzing the Change Rate of Phase Angle at High Frequency

摘要

Some parameters are valuable in analyzing the organic coating performance such as coating resistance,coating capacitance, charge transfer resistance, double layer capacitance, while their extraction fromEIS data is usually time-taking, furthermore, there may be some errors in calculating EIS data withequivalent circuit method. In this paper an attempt is made to introduce a new parameter obtained fromthe change rate of phase angle of Bode at high frequency in the electrochemical impedancespectroscopy (EIS) data. The new parameter () then proved to be effective when evaluating theprotective performance of a kind of grey organic coating used in vehicle equipment. The resultsindicated that this parameter has a good agreement with the phase angle at middle frequency of 10 Hzand the phase angle at high frequency of 10k Hz, respectively. It is concluded that the parameter canbe used for fast evaluation of organic coatings in practical application.