Sulfurized DOPO synergizes with phenoxytriazine to impart epoxy thermoset fire safety, thermal stability and mechanical toughness

Fire dangers have grown to be a serious potential issue that could endanger people's health and safety in recent years. A lot of emphasis has been paid to the employment of straightforward techniques to create multifunctional synergistic flame retardants in order to create multifunctional flame retardant epoxy curing compounds. In this paper, a flame retardant TFD with DOPS and phenoxytriazine as flame retardant core groups was synthesized by molecular structure design using cyanuric chloride, p-hydroxybenzaldehyde, and DOPS as the raw materials, and it was melt blended with EP to construct a flame retardant thermoset resin EP/TFD. The results show that the addition of only 10% TFD enables EP to pass the UL-94 V-0 test with an LOI of up to 35.3%. Moreover, TFD was able to effectively reduce the peak heat release rate, total heat release, and fire growth index of epoxy curing compounds, whereas the fire performance index was significantly improved compared with that of pure EP, indicating that TFD could confer higher fire safety to EP. Moreover, TFD can significantly enhance the mechanical toughness of EP with appropriate additive amount. That is, the maximum rise compared with the pure EP enhancement of 46.3%. This program serves as a valuable resource for the advancement of halogen-free flame retardants with superior efficiency.