Simultaneously Improving the Thermal, Flame-Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi-Element Synergistic Flame Retardant

To obtain epoxy resins with satisfactory thermal, flame retardant, and mechanical properties, a novel multi-elementsynergistic flame retardant (PPVSZ) is synthesized through the reaction between PH of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and CC of polysilazane (PVSZ) and utilized as a multi-element synergistic flame retardant for epoxy resins. The flame retardant mechanism is explored by XPS and SEM, confirming that the excellent flame-retardance efficiency owes itself to an optimal flame retardant way which jointly exerts the flame-retardant effects in the gaseous and condensed phase. The thermal properties deduced from DSC, TGA, and DMA, indicate the glass transition temperature, maximum weight loss rate, and char yields at 700 degrees C for EP-2 increase by about 5.0 degrees C, 8.4 degrees C and 8.8%, respectively. Furthermore, mechanical properties such as impact strength, tensile strength, and flexural strength are also increased by 45.38%, 14.16%, and 17.43%, respectively, which show that the incorporation of PPVSZ does not deteriorate the mechanical properties of modified resin. All the results demonstrate that epoxy resins modified by PPVSZ not only have good effect on the flame retardance, but also have good improvement on thermal and mechanical properties, indicating the potential for applications in many fields requiring fire safety.