J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (12): 2464-2471.DOI: 10.1016/j.jmst.2018.05.009

Special Issue: Corrosion in 2018

• Orginal Article • Previous Articles     Next Articles

Corrosion protection of waterborne epoxy coatings containing mussel-inspired adhesive polymers based on polyaspartamide derivatives on carbon steel

Mingliang Yangac*(), Jianhua Wuabc*(), Daqing Fangc, Bo Lic, Yang Yangc   

  1. a College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
    b State Key Laboratory for Marine Corrosion and Protection, Qingdao 266101, China
    c Xiamen Sunrui Ship Coating Co., LTD., Xiamen 361101, China
  • Received:2017-12-05 Revised:2018-01-04 Accepted:2018-01-18 Online:2018-12-20 Published:2018-11-15
  • Contact: Yang Mingliang,Wu Jianhua

Abstract:

A novel mussel-inspired adhesive polymer (PHEA-DOPA) containing the 3,4-dihydroxyphenylalanine (DOPA) functional group based on polyaspartamide derivatives was synthesized. The corrosion protection of the waterborne epoxy coatings containing the adhesive polymers was investigated by electrochemical impedance spectroscopy (EIS). The results indicated that the PHEA-DOPA could improve the corrosion resistance of the waterborne epoxy coating. The corrosion products were also analyzed by Raman microspectroscopy (RM), indicating the formation of the insoluble DOPA-Fe complexes on the carbon steel surface. These complexes simultaneously acting as a passivating layer, can inhibit the process of corrosion at the metal-solution interface. The differential scanning calorimeter (DSC) measurement indicated that PHEA-DOPA can increase the crosslinking density of coating. The effect of O2 on the protective mechanism of the PHEA-DOPA coating in a 3.5% NaCl solution was also evaluated by EIS. The results indicated that the barrier effect was significantly improved under aerated conditions because DOPA was oxidized to DOPA-quinone (Dq) by O2, which triggered the reaction with Fe ions that were released from the surface of the carbon steel. This led to more compact coatings.

Key words: Corrosion protection, Adhesive polymer, Inhibito, Waterborne, PHEA-DOPA