Study of the anti-bacterial and anti-corrosion of Zinc Pyrithione-based composite coating

摘要

In order to control microbiological influenced corrosion (MIC) in the oilfield pipelines, the anti-bacterial coatings were the most used ways. In this paper, we have studied the anti-bacteria of the epoxy resin composite coating, using Zinc Pyrithione(ZPT) as the anti-bacteria material. It is an efficient and easily method to apply antimicrobial coating onto the surface of the pipe. Therefore, this paper systematically researched its bactericidal properties to sulfate reducting bacteria(SRB). Electrochemical measurements and surface analysis were used to investigate the anti-bacterial and anti-corrosion performance of ZPT composite coating. Results show that ZPT could effectively kill SRB, inhibiting their adhesion onto the surface of Q235 carbon steel and the formation of bio films. Due to the addition of ZPT, it blocked the microscopic pore formed during the process of solvent-free epoxy crosslinking, so that the corrosive media could not contact with the metal substrate directly, thus effectively inhibiting MIC on the surface of Q235 carbon steel. Potentiodynamic polarization data shows that the corrosion current density in the presence of ZPT composite coating was lower than the pure epoxy resin coating (Table l).This means that the corrosion of coupon can be inhibited in the presence of ZPT. The results also indicated the ZPT composite coating could effectively inhibit SRB corrosion.