Per: João Pedro gonçalves santiago lima (LABORATÓRIO DE PESQUISA Em CORROSÃO (LPC)), WALNEY SILVA ARAUJO (LABORATÓRIO DE PESQUISA Em CORROSÃO (LPC)), Otilio Braulio Freire Diógenes (LABORATÓRIO DE PESQUISA Em CORROSÃO (LPC)), Bruno Gomes Linhares (LABORATÓRIO DE PESQUISA E CORROSÃO (LPC))
Abstract:
Under atmospheric conditions, carbon steel structures are subject to the electrochemical corrosion process, and the coal tar epoxy coating is an efficient mechanism to inhibit or delay this process. However, due to the damage to human health caused by coal tar, its use has been banned in countries such as the United States and Japan. Alternatively, a kraft lignin-based coating, a by-product of the pulp and paper industry, is proposed. For better utilization, the lignin underwent a process of acetylation, promoting good compatibility with the epoxy system diglycidyl ether of bisphenol A (DGEBA), forming a set epoxy resin-lignin being the acetylated lignin added to the resin DGEBA. In the work, the epoxy coating was added lignin, in concentrations of 7.5% and 15% and exposed to atmospheric conditions of urban and marine-industrial environments to obtain information about the behavior of coatings in these conditions. To quantify and better evaluate the behavior against corrosion of these coatings, the electrochemical impedance spectroscopy (EIE) technique was used. The results showed that the coatings added with acetylated lignin presented a better performance than the DGEBA coating without acetylated lignin. Additionally, comparing the two environments, the coatings showed better results in exposure to a urbane atmosphere.