Corrosion resistance of polyvinyl butyral/reduced graphene oxide/titanium dioxide composite coatings for stainless steel in different environments

An environmentally friendly composite material, combining polyvinyl butyral (PVB), reduced graphene oxide (rGO) and modified nano titanium dioxide (TiO2-KH550), was prepared by facile mechanical agitation. The mixed filler of rGO and TiO2-KH550 was introduced into coating to improve anti-corrosion capability of 304 stainless steel in diverse environments. The tested results of surface morphology showed that mixed filler was uniformly dispersed into PVB, and composite coatings were smooth without cracks and holes. According to the results of electrochemical impedance spectroscopy with different corrosive environments, PVB/rGO/TiO2-KH550 coating exhibited the maximum value in low-frequency impedance (|Z|0.01Hz) and charge transfer resistance (Rct). The long-term immersion test was processed in 3.5 wt% NaCl solution at room temperature. The result demonstrated that the PVB/rGO/TiO2-KH550 coating effectively protected the substrate for over 430 days. This work provides an ideal approach of using hydrazide compounds to prevent metal corrosion.