Intumescent Flame Retardant/Nano-CuO Synergistic Flame-Retardant Epoxy Resin

The expansion flame retardant system containing monomolecular intumescent flame retardant 2,4,6-tris (2,4-bis (5,5-dimethyl-1,3-dioxacyclohexylphosphoryloxy) phenyl) -1, 3,5-triazine (TDDMDOBT) and ammonium polyphosphate (APP) was applied to the flame retardant modification of epoxy resin, in order to improve its smoke toxicity and mechanical performance, CuO was introduced into the optimal formulation EP5 of the flame retardant system to prepare the flame retardant epoxy resin (EP). The test results show that the material which presents the best comprehensive performance in the CuO synergy system is EP31 (m(TDDMDOBT-APP)/m(CuO)/m(EP) = 19/1/80). The oxygen index of the material is 50%, and the flame retardancy is significantly increased. In the thermogravimetric experiment, the pk-HRR is reduced by 70.1% and 98.2% compared with EP5 and pure epoxy resin(EP0) respectively, indicating that the stability of the material under external radiant heat source is significantly improved; in the CONE test, the av-SEA of material is reduced by 77.5% and 70.3% respectively compared to EP5 and EP0; through the SEM measurement, it is found that EP31, when heated, can generate a cross-linked carbon layers with nano particles as node. The carbon layers are dense and have a large amount of carbon, which have a good carbon formation effect; the mechanical property tests show that the impact strength, tensile strength, bending strength and elongation at break of the material are increased by 39.7%, 23.9%, 96.2%, and 49.8%, respectively, indicating that the mechanical properties of the material are improved. © 2020, Editorial Board of Polymer Materials Science & Engineering. All right reserved.