Advanced Epoxy-Based Anticorrosion Coatings Containing Graphite Oxide

A cycloaliphatic epoxy resin was used as polymer matrix where graphene oxide (GO) was directly dispersed in the range between 0.05 and 1.0 wt % by ultraturrax mixing, followed by sonication. A cationic photoinitiator was added in the proper amount and the formulations were coated on poliethylene (PET) or steel substrates and ultraviolet (UV) light irradiated. Transparent UV-cured films were obtained and tested as protective coatings in terms of water permeability and corrosion protection. Water vapor transmission rate (WVTR) was determined by permeometer measurements compared with untreated PET samples while impedance measurements on the coated steel plates, in contact with an aggressive corrosive solution, were carried out to assess the efficience as corrosive protective coatings. Promising results were obtained in both cases, in particular on low GO loaded samples, attributed to the good dispersion of GO in the polymer matrix. The progress of the photopolymerization process was followed by real time Fourier Transform Infrared Spectroscopy (FTIR). Moreover, static contact angle was determined with water, the surface morphology of the films was investigated by Field Emission Scanning Electron Microscopy (FESEM) while the film transparency was measured by UV-vis spectrophotometer. The obtained results are comparable and even better than those reported for other polymer/inorganic composites, even though using very low amounts of GO dispersed in the polymeric matrix, suggesting many potential applications in anticorrosive coatings, electronic devices, pharmaceuticals and food packaging.