Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1146-1152.doi: 10.3866/PKU.WHXB201202272

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Electrochemical Impedance Spectroscopy Study of Failure Process of an Epoxy/Fluorocarbon Coating System

PANG Ran, ZUO Yu, TANG Yu-Ming, XIONG Jin-Ping   

  1. Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
  • Received:2011-12-30 Revised:2012-02-17 Published:2012-04-26
  • Contact: ZUO Yu E-mail:zuoy@mail.buct.edu.cn
  • Supported by:

    The project was supported by the National Key Technologies R&D Program of China (2007 BAB 27 B04).

Abstract: The failure processes of a multi-layer coating system (zinc-rich epoxy primer, epoxy middle layer, and fluorocarbon topcoat) in four corrosion environments were studied with electrochemical impedance spectroscopy (EIS). The failure rate of the coating system in the four environments decreases in following order: immersion in a 3.5% NaCl solution under UV light, steam above a water surface at 45 ℃, salt spray at 35 ℃, and immersion in a 3.5% NaCl solution at room temperature. Although the failure rates of the coating system in the four environments are different, the variations of the phase angles at the middle frequency range, particularly 10 Hz, are very close to that of the coating impedance; hence they may be used as a qualitative evaluation parameter for coating inspection.

Key words: Fluorocarbon coating, Electrochemical impedance spectroscopy, Performance, Failure, Fast evaluation, Phase angle

MSC2000: 

  • O646