A free hydroxyl-containing benzoxazine monomer was synthesised using bio-based card phenol, paraformaldehyde and ethanolamine by a Mannich condensation reaction. The hydroxyl-containing benzoxazine monomer synthesised was characterised by FT-IR spectroscopy. Curing of the benzoxazine was monitored by using Differential Scanning Calorimetry (DSC). The free hydroxyl group in the benzoxazine monomer helps to enhance the adhesion of polybenzoxazine coating with the metal substrate. The synthesised benzoxazine was copolymerised with an epoxy resin and a saturated polyester resin for potential coating applications and their curing was monitored using DSC and FT-IR spectroscopy. The benzoxazine-epoxy copolymerised system demonstrated enhanced mechanical, chemical and thermal properties compared to the benzoxazine-saturated polyester system as well as compared with neat polybenzoxazine.