Phenolated Oleic Acid Based Polybenzoxazine Derivatives as Corrosion Protection Layers

Benzoxazine derivatives were synthesized using phenolated methyl oleate and either aniline, 1,6-diaminohexane, or 4,4-diaminodiphenylmethane, respectively, as amine components. Polymerization of the benzoxazine derivatives led to the formation of hydrophobic and dense coatings on Zn-Mg-Al alloy coated steel sheets for passive corrosion protection. The polybenzoxazine coatings which are formed by crosslinking during a heat-treatment step invoked a substantial anodic shift of the open-circuit potential as well as the breakthrough potential in potentiodynamic measurements. The proposed polybenzoxazine derivatives pave the way for a new type of passive polymer protection system based on sustainably obtained precursor components.