Porous Density Influence on Anti-Corrosive Epoxy Resin-Based Coat Reinforced with Reduced Graphene Oxide (rGO)

The corrosion resistance of an epoxy resin-based coat, reinforced with 0.1 and 0.5 wt% of reduced graphene oxide (rGO), applied to AISI 1020 carbon steel was subjected to immersion tests on a 3.0 wt% NaCl solution saturated with CO₂ in a pressurized cell with 70 bar at 40 °C for 528 hours. The coating was accessed via pull-off testing, and scanning electron microscopy (SEM) was used to analyze porosity and thickness. Optical Microscopy (OM) assessed the condition of the metallic surface. Adding rGO generated greater corrosion protection and improved the structural integrity of the coating for the conditions studied. With 0.1 wt% rGO, there was a pore refinement, and with 0.5 wt%, pore density was drastically reduced. The addition of rGO did not influence the coating Shore D hardness coating. Post-corrosion test results indicated that porosity and solution permeation were related, and the anchorage of the coating to the substrate was not affected.

Keywords:
CO₂ Corrosion; Reduced Graphene Oxide; Pore Refining; Nanocomposite; Novolac Epoxy Resin