A facile one-step synthesis of highly efficient melamine salt reactive flame retardant for epoxy resin

In order to improve the flame retardancy and smoke suppression of epoxy resin (EP) simultaneously, we synthesized a melamine phenylhypophosphonate named as MABP via a simple one-step method and used it to modify EP materials. As expected, the addition of MABP not only largely improved the flame retardancy but also restrained the smoke release of EP. For details, when the content of MABP was 10 wt%, the EP composite possessed a limiting oxygen index value of 33% and achieved to a UL-94 V-0 rating as well as its PHRR, THR and TSP values decreased by 55.1%, 27.1% and 60% compared with that of neat EP, respectively. In addition, the flame-retardant mechanism was investigated by multiple instruments, and the corresponding results exhibited that the MABP could improve the compactness of char layer in condense phase and exerted fire-inhibition effect in gaseous phase. Graphic abstract