Corrosion is a significant issue with metallic materials, notably in steel due to its extensive use in a variety of industries. Benzoxazine polymers have been used to produce anti-corrosive compounds that have a remarkable ability to limit corrosion. In the same ink line, we have explored a new approach with a very hydrophobic benzoxazine monomer which is co-polymerized with urethane, and its characterization was studied with IR, UV, and NMR techniques. The corrosion resistance of the same is investigated using Tafel polarization and EIS experiment methodologies. The DFT and MEP studies explain the reactivity towards the anti-corrosive properties of the monomer.