Effect of methyl methacrylate/nitrile rubber/graphene oxide on the anticorrosion and mechanical properties of epoxy‐based coating

Abstract Graphene oxide has a wide application prospect as filler due to its excellent physical blocking, coating reinforcement, and cathodic protection properties. However, graphene oxide is highly susceptible to agglomerative reunions. Three types of anti‐corrosion coatings were prepared on 5083 Al alloy by a simple smearing method. The coatings are based on neat epoxy resin by introducing different amounts of graphene oxide, methyl methacrylate/nitrile rubber, and methyl methacrylate/nitrile rubber/ graphene oxide fillers. Thermogravimetric analysis (TGA) results show that methyl methacrylate/nitrile rubber/graphene oxide fillers enhance the thermal stability of the epoxy resin‐based coatings. The SEM morphology shows the well‐dispersed methyl methacrylate/nitrile rubber/graphene oxide in the coating. The 2 and 1 wt% methyl methacrylate/nitrile rubber/graphene oxide coating exhibits excellent mechanical properties and outstanding anti‐corrosion properties, respectively. At 1 wt%, the OCP of the coating is −0.21 V. Additionally, the coating exhibits great anti‐corrosion performance after immersion for 196 h. Compared to the pristine coating and methyl methacrylate/nitrile rubber coatings, the methyl methacrylate/nitrile rubber/graphene oxide coatings show better thermal stability, mechanical properties and anti‐corrosion properties. The methyl methacrylate/nitrile rubber fillers degrade the thermal stability and anti‐corrosion protection and do not affect mechanical properties. Compared with graphene oxide coatings, the surface of methyl methacrylate/nitrile rubber/graphene oxide coatings is smoother with better dispersion, possessing better mechanical and anti‐corrosion properties though only a fewer amounts of graphene oxide were filled in epoxy resin. The better corrosion resistance of the coating can be attributed to the synergistic effect of a physical barrier and a coulomb block.