Investigação do efeito da adição de nanopartículas no desempenho anticorrosivo de revestimento poliaspártico

Abstract

The present study aims to investigate the influence of graphene-based and nano-copper nanoparticle additives on the anti-corrosive performance of a commercial polyaspartic coating. Based on the premise that nanotechnology can enhance the protective properties of organic coatings, this research comparatively evaluates the neat formulation and the versions containing these nanoparticles. The experimental methodology involved carbon steel substrates, with surface preparation and coating application performed by a partner company specializing in nanotechnology, which also provided the samples. Subsequently, the specimens were subjected to two distinct degradation scenarios. The first involved natural weathering in an urban atmospheric corrosion environment at the Federal University of Ceará (UFC) Pici campus. The second scenario employed accelerated salt spray chamber tests, simulating a highly aggressive marine environment. To quantitatively analyze performance, several characterization techniques were employed. Coating-to-substrate adhesion was evaluated using the pull-off test method. Barrier properties and resistance to electrolyte penetration were investigated using Electrochemical Impedance Spectroscopy (EIS). Furthermore, the protective system's capacity to retard corrosion progression starting from a deliberate scribe in the film was evaluated. In addition, periodic visual inspections were conducted through weekly photographic records to document the evolution of defects such as blistering, the formation of corrosion products, and the overall progression of the degradation process. The study concluded that adding nanoparticles to the polyaspartic coating did not improve anti-corrosive performance under the evaluated conditions and, in several scenarios, had an adverse effect. In atmospheric corrosion tests (UFC), the neat coating demonstrated exceptional barrier performance (109 Ω · cm2), outperforming the nano-additive systems. However, in the salt spray environment, all systems (both neat and additivated) exhibited poor protection (below 106 Ω · cm2). A critical limitation identified in both exposure conditions was the poor adhesion of all samples to the carbon steel substrate, which failed to meet the minimum adhesion requirement (8 MPa) of the Petrobras N-2943:2022 standard.