Synthesis of eugenol-modified epoxy resin and application on wood flame retardant coating

In this paper, a novel epoxy flame retardant PPDEG-EP (P-E) was synthesized from eugenol by nucleophilic substitution reaction and Prilezhaev epoxidation. The chemical structure was identified by nuclear magnetic resonance (NMR). The synthetic P-E was combined with curing agent diaminodiphenylmethane (DDM) and applied to wood surface coating decoration. To evaluate the thermal curing behavior of P-E, the P-E/DDM system was characterized by DSC. The results show that P-E/DDM has a lower reaction activation energy (Ea), and the curing temperature of the system is reduced with the incorporation of P-E. As a wood coating, P-E/DDM retains the excellent physical and chemical properties of epoxy resins. Thermogravimetric (TG) showed the char formation of P-E/DDM was improved, that the char residue of P-E/DDM+W was higher than both that of pure wood and P-E/DDM. And it produced significant flame retardancy that the UL-94 test reached V-0 rating and the value of LOI test was 32.1%. As expected, SEM shows that the internal structure of the burned wood was still intact. This eugenol-modified coating has been proved to be a good flame retardant for wood.