Facile synthesis and construction of renewable, waterborne and flame-retardant UV-curable coatings in wood surface

Exploring facile synthesis and organic-solvent-free of renewable flame-retardant coatings in wood surface is in line with the environmental protection and safety. In this research, acrylated epoxidized soybean oil (AESO), flame retardant FRC-6, and itaconic anhydride (IAH) were used to prepare waterborne unsaturated resins (IAESO) and monomers (IAFRC) in one pot through esterification. The waterborne coatings consisting of IAESO and IAFRC appeared favorable dispersity, and applied to prepare flame-retardant UV-curable coatings in wood surface, which presented eligible physical properties including pencil hardness, adhesion, and solvent resistance. Meanwhile, IAESO-F20-W exhibited prominent flame retardancy with UL-94 V-0 rating and the highest LOI value of 28.9 %, which improved significantly comparing with pure wood. Further, IAFRC obviously enhanced the overall carbonization and produced the dense char layer covering on the substrate surface, which hindered the transfer of heat, smoke, and combustible volatiles, thereby effectively suppressed the further combustion and pyrolysis of substrate, demonstrating that the waterborne flame-retardant UV-curable coatings ameliorated wood flammability effectively. • One-step modification from IAH availably improved the water-dispersibility of resins. • The whole preparation process was eco-friendly, simple, and efficient. • The UV-curable coatings evidently enhanced the flame retardancy of wood. • IAFRC played an important role in condensed and gas phases flame retardant effect.