Synthesis of MnO2 nanoparticles with different morphologies and application for improving the fire safety of epoxy

MnO2 exhibits excellent catalysis properties, which is expected to improve the fire safety of epoxy resin. In this work, MnO2 particles with different morphologies and different crystalline structures were used to reduce the fire hazards of epoxy resin. TEM ultrathin observation results indicated that nanorods and nanosheets were well dispersed in epoxy matrix. Moreover, α-nanosheets improved the thermal stability of epoxy composites, performing better than β-nanorods and α-nanospheres. The combustion performance investigated by cone calorimeter showed that α-nanosheets based composites exhibited the lowest peak heat release rate, total heat release, smoke production rate and total smoke production values. TG-IR results indicated that α-nanosheets performed the best to inhibit the permeation of volatile gases. The reason is probably due to the synergistic effect by physical insulting effect and catalytic charring of the layered structure.