Comparative corrosion protection studies of electroactiveon-electroactive epoxy thermoset composites containing conductive rGOon-conductive GO platelets

摘要

In this study, comparative corrosion protection studies of cold-rolled steel (CRS) electrodes coated with electroactiveon-electroactive epoxy thermoset (denoted as EET/NEET) composites containing dispersed reduced grapheneoxide (rGO) and graphene oxide (GO) platelets are presented. All composites were obtained through the thermal ring-openingreaction of bisphenol A diglycidyl ether (DGEBA) with amino-capped aniline trimer (ACAT) or trimethylolpropanetris[poly(propylene glycol), amine terminated] ether (T-403) at a specific mixing ratio in the presence of dispersed rGO/GOwere characterized Fourier Transform Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). In gaspermeability measurements, the GO was found to display a slightly better dispersion capability in both EET and NEETmembrane than in rGO. Conductive rGO platelets were found to promote the redox behavior of EET and non-conductiveGO platelets was found to depress the redox behavior of EET, as measured by electrochemical cyclic voltammetry (CV)studies. Corrosion protection of composite coatings was investigated by electrochemical corrosion measurements in salinesolution. It should be noted, in the EET system, that rGO was found to exhibit better anticorrosion performance as comparedto that of GO. However, in NEET system, GO was found to have better anticorrosion performance than rGO. Better anticorrosionof rGO in EET may be attributed to better synergistic effect of electro-catalytic and the oxygen barrier propertiesof rGO in EET. On the contrary, better anticorrosion of GO in NEET may be associated with better oxygen barrier propertyof GO alone in NEET than that of rGO. The passive metal oxide layer formed on the cold rolled steel (CRS) electrodeinduced by EET was further confirmed by Raman and Electron Spectroscopy for Chemical Analysis (ESCA).