Study and Assessment of the Efficiency of the Cocoa Bark Extracted from the Theobroma Cacao as an Inhibitor of the Corrosion of Carbon Steel in Substitution of Benzotriazole

Abstract

Corrosion represents high losses to the economy, therefore, researches on the minimization of its damages in materials, mainly the metallic ones, are necessary. Among the various alternatives of protection against corrosion, there is the application of corrosion inhibitors that can minimize or even stop the corrosive process of metallic materials. However, at present, substances usually used as corrosion inhibitors present high toxicity, being considered harmful components to the environment and to human health. Therefore, there is an urgent need for studies on viable corrosion inhibitors, by considering not only economic but also environmental costs. The present work studied the use of cocoa bark extract (Theobrama cacao L), for possible replacement of benzotriazole (BTAH) in the corrosion inhibition of ASTM 1020 carbon steel (CS-ASTM 1020) in 18.23 g.L -1 hydrochloric acid media. Weight loss measurements, anodic and cathodic potentiodynamic polarization curves and electrochemical impedance experiments were carried out. The results showed that the addition of the extract to the electrolyte effectively hinder the corrosion process and indicated its adsorption on the electrode surface. In addition, the inhibiting efficiency of the cocoa bark extract was only slightly inferior to BTAH, showing that it can be an environmentally friendly option to toxic inhibitors.

Microrganismos Na Biodegradação De Polímeros Em Meio Aquoso

“…Na região entre 2917-2849 cm -1 é possível verificar a presença de duas bandas estreitas atribuídas ao estiramento simétrico e assimétrico das ligações C-H dos grupos CH3, CH2 e CH, conforme também observado por Barreto et al (2018).…”

“…A partir da sobreposição dos gráficos de Nyquist, com o objetivo de comparar a eficiência da inibição da corrosão nas diferentes concentrações do sinergismo da casca da mamona com a casca do cacau (Fig 3a), foi possivel observar a ocorrência do arco capacitivo achatado, cujo o diâmetro é sempre maior na presença dos inibidores em relação ao ensaio branco, indicando atividade anticorrosiva, pois os inibidores formam uma película protetora na interface metal-solução. Comportamento similar foi observado em outros trabalhos na literatura (PERIÑÁN et al, 2016;SANTOS, et al, 2017;BARRETO, et al, 2018, SANTOS, et al 2020).…”

“…Já as densidades de corrente catódicas ( Fig.5b) para as amostras com inibidores são menores que da amostra sem inibidor. Os resultados corroboram com a literatura, Barreto et al 2018 e Almeida 2017, estudaram a atividade anticorrosiva de um resíduo, sendo que nesses estudos, o inibidor avaliado foi a casca do fruto do cacau e, para esse caso, também observaram um comportamento anódico para o inibidor.…”

Effect of water-soluble chitosan on the electrochemical corrosion behaviour of mild steel

“…A lot of methods have been used to combat the attack of corrosion on mild steel but the use of inhibitive particulates have been found effective and applicable [11][12][13] . Most inhibitors have been found to be relatively cheap, environmentfriendly and also pave way for easy reproducibility [14,15] . A good example is the chitosan found to be richly available in the [16] .…”

“…A good example is the chitosan found to be richly available in the [16] . Its broad range of application can be attributed to its unique properties, which include non-toxicity, bio-compatibility, bio-degradability and great film forming capability on steel [15][16][17] . Chitosan's anti-corrosion capability is also a function of its molecular structure.…”