A novel and convenient zeolite modification strategy for enhancing the fire resistance of epoxy resin

The preparation process of new environmentally friendly flame retardants to endow epoxy resin (EP) with excellent flame retardancy and mechanical properties remains a challenging task. In this study, a novel Zeolite@DPA-Cu flame retardant was designed and prepared by a simple and environmentally friendly aqueous preparation process using zeolite, copper sulfate and diphenylphosphonic acid as main raw materials. As expected, Zeolite@DPA-Cu significantly improved the flame retardancy and mechanical properties of EP composites. The results showed that the LOI and UL-94 grade of the EP/5 wt% Zeolite@DPA-Cu composite reached 32.4 % and V-0 rating, respectively. The synergistic effect of the physical barrier, free radical capture and catalytic char formation of Zeolite@DPA-Cu significantly improved the flame retardancy of EP. In addition, due to the strong interfacial interaction between Zeolite@DPA-Cu and EP, the tensile strength and elongation at break of the EP were increased to 57.92 MPa and 4.7 %, respectively. Generally, this study proposed a modification strategy that takes into account both flame retardancy and mechanical properties, which is extremely important for the practical application of EP flame retardant materials.