Study on the aging characteristics of flexible graphite composite grounding material under acidic and alkaline environments

Reliable grounding systems are essential for ensuring the safety, stability, and operational efficiency of power networks. In this study, a flexible graphite composite grounding material (FGCGM) was subjected to accelerated aging under acidic and alkaline conditions to investigate its long-term durability in corrosive environments. The results indicated that the materials exhibited excellent resistance to acidic corrosion (5 wt. % H2SO4). Conversely, graphite particles were more prone to detachment in an alkaline environment (5 wt. % NaOH), which resulted in an average weight change of 1.710% and a 10.638% increase in bulk resistivity. To further elucidate the mechanism of graphite particle detachment, molecular dynamics simulations were conducted based on the adhesive components of the test specimens. As indicated by the simulation results, ethyl acrylate adhesives were found to be more susceptible to hydrolysis in an alkaline environment (5 wt. % NaOH). In comparison with acidic environments (5 wt. % H2SO4), a greater quantity of gaseous by-products and ethanol was produced. In addition, this study examined two other commonly used adhesive components in FGCGM—epoxy resin and polyurethane (PU). It was found that PU adhesives exhibited superior stability in acidic environments, whereas epoxy resins demonstrated better performance under alkaline conditions. These findings provided engineering guidance for the selection and maintenance of grounding materials in substations and high-voltage transmission facilities, particularly in regions with aggressive soil chemistry.