Síntese de novo composto imínico com atividade antioxidante e anticorrosiva aplicado em biodiesel de soja

Abstract

Biodiesel is a renewable biofuel produced from transesterification of vegetable oils and animal fats with short-chain alcohols. Despite being environmentally friendly, biodiesel has low oxidative stability and is gradually degraded by autooxidation reactions. Furthmore, metallic structures are corroded whenimmersed in biodiesel, for being a higher electric conductive (compared with petro diesel) and hygroscopic medium. To rise oxidative stability and not damage fuel engines and storage tanks, antioxidants (reduce catalytic radical reactions) and corrosion inhibitors (adsorbs on metallic surface) are added in biodiesel. In this dissertation are discussed the synthesis of the new phenolic-iminic compound N,N’-bis-(4-hexadecanoate)salicylidene-ethylenedimaine,named IM, to play as multifunctional molecule, exhibiting antioxidative and corrosion inhibition activity. IM reduced carbon steel AISI 1020 coupons immersed in biodiesel, at room temperature and under heating and showed better results than commercial compounds butylated hydroxytoluene (BHT), tert-butylhydroquinone (TBHQ) and pyrogallol (PY). IM also increased oxidative stability of biodiesel contaminated with cooper ions, working as metal chelator, and reduced dissolved oxygen in biodiesel, working as oxygen scavenger. Corrosion was evaluated by light microscopy, scanning electron microscopy and atomic force microscopy. Oxidative stability tests were made by PetroOXY method