Eficiência de Anacardium occidentale Linn em um sistema microemulsionado na inibição a corrosão de aço carbono

Several studies applied to control corrosion process using natural compounds were undertaken in the recent decades. In that, the natural compounds effectiveness on metallic corrosion inhibition represents an alternative for sustainable technological development. In general, among the widely used methods for corrosion inhibitors surfactant compounds have been cited as effective agents with protective films action on the anodic and cathodic areas. In this present work the ethanolic extract obtained of the stem bark of Anacardium occidentale Linn (AO) solubilized in a microemulsion system (SME) was applied as natural corrosion inhibitor. The rich O/W microemulsion system was obtained with OCS (surfactant), butanol (cosurfactant) and kerosene as organic phase. The effectiveness of the polar extract AO solubilized in the microemulsion SME-OCS-AO was analyzed by electrochemical method of polarization resistance. In that, the content of the natural inhibitor AO ranging from 50 to 400 ppm, in saline solution (3.5 % NaCl). The observed maximum inhibition efficiencies (95.68 %) showed an adsorption phenomena of the SME-OCS-AO according to the polar extract (AO) concentration, in which the adsorption of SME-OCS-AO obeys Langmuir adsorption isotherm. Palavras-chave: Corrosion inhibitor; microemulsion; Anacardium occidentale.