Incorporation of electroconductive carbon fibers to achieve enhanced anti-corrosion performance of zinc rich coatings

Abstract

Zinc rich epoxy (ZRE) coatings can provide sacrificial anode protection for metal substrate. Electrically conductive fillers can be added into ZRE coatings to create electroconductive network and improve the utilization of zinc particles. Inspired by the structure of reinforced concrete, in this work, carbon fibers with a length of 2 mm, 5 mm, and 10 mm were used as electrically conductive fillers to drive more zinc particle into electrically conductive paths and to provide coatings with better mechanical properties. Without agglomeration, ZRE-10 can achieve an efficient protection for copper substrate up to 50 days in 3.5 wt% NaCl solution, much longer than that of ZRE coating. Moreover, the fraction of water absorbed by ZRE-10 is 14%, which for ZRE is 20%, and the adhesion strength of ZRE-10 increased by 65% compared with that of ZRE. All tests in this work can prove a remarkably enhanced anticorrosion performance and mechanical properties of ZRE coatings achieved by addition of longer carbon fibers.