Structure–property relationships and barrier performance of graphene oxide-reinforced epoxy–acrylate coatings for aggressive environments

Abstract

Epoxy–acrylate GO-reinforced coatings reinforced with graphene oxide (GO) were developed to improve barrier performance in aggressive environments. GO nanosheets (1–3 wt.%) were incorporated into the polymer matrix using a controlled dispersion approach, followed by thermal curing to obtain crosslinked coatings. Thermal analysis showed enhanced stability: the 5% mass loss temperature (T5%) increased from 305 °C for pure epoxy resin to 320 °C for GO-modified systems, and the char residue also increased. Dynamic mechanical analysis revealed higher stiffness and a shift of the glass transition toward lower temperatures, indicating the formation of a heterogeneous network structure. Mechanical testing demonstrated a decrease in tensile strength (28.3 to 23.8 MPa) and elongation, while hardness increased significantly (from 81.3 to 95.7 Shore units) and curing shrinkage was reduced. Chemical resistance was significantly improved: absorption in acidic environments decreased from 28% to ~15.9%, while even lower values ??were observed in alkaline and saline environments. These improvements are attributed to interfacial interactions between GO and the polymer matrix and the formation of a tortuous diffusion pathway that limits the transport of aggressive species. Overall, the results demonstrate that optimized GO incorporation enhances the durability and barrier properties of epoxy–acrylate coatings, despite a reduction in mechanical ductility at higher loadings.