Cobalt and Nickel ZIF/MXene Nanohybrids as Flame Retardants for Epoxy Polymers

To improve the interface interaction between MXene and the polymer matrix, CoNi-ZIFs were adopted to modify MXene through an in situ preparation method. The nanohybrid flame retardants were introduced into epoxy polymers (EPs) to improve the thermal stability, flame resistance, and smoke reduction capabilities of the EP nanocomposites. Based on the above design, the nanohybrid flame retardants exhibit excellent synergistic flame retardant effects. Compared with the MXene and CoNi-ZIF-based EP nanocomposites, the performance in terms of thermal stability, flame resistance, and smoke reduction capabilities of EP/CoNi-ZIF/MXene nanocomposites has been significantly improved. 2 wt % CoNi-ZIF/MXene in EP can improve the residual carbon content of nanocomposites to 18.78% at high temperature and reduce the peak heat release rate (pHRR) by 22.68%, and the release of the smoke production rate (SPR), CO, and CO2 for the nanocomposites is also inhibited simultaneously. The notable decrease in the fire risk of EP largely stems from the catalytic carbonization of transition metals and the synergistic and physical barrier effects of the CoNi-ZIF/MXene nanohybrids.