Effect of graphene oxide on wear resistance of polyester resin electrostatically deposited on steel sheets

Electrostatically deposited polyester resin powder coatings have been extensively used for painting in industrial applications. Furthermore, protective coatings are used to prevent the deleterious effects on the substrate in varying environmental conditions. The present study investigated the tribological behavior of polyester resin coatings containing three different amounts of added graphene oxide (GO): 100, 200, and 300 mg/kg, which were electrostatically deposited on steel sheets. Polyester resin coating without GO was used as control. Coatings were characterized using optical microscopy, scanning electron microscopy, atomic force microscopy, Raman spectroscopy, spectrophotometry, and nanoindentation testing. Additionally, dry contact pin-on-disc testing was used to evaluate the tribological behavior of the polyester resin coatings. The results indicated that graphene nanoparticles were uniformly distributed throughout the electrostatically deposited coatings after the thermal polymerization process. Optical spectroscopy results indicated minor variations in reflectance and slight changes in color of the analyzed samples. Tribological tests indicated that when the amount of GO incorporated into polyester resin increased, the wear values and coefficients of friction of the coatings significantly decreased. These results demonstrated the beneficial effect of the self-lubricating properties of GO on improving the resistance of the coatings.