Simultaneously improving the fire safety and mechanical properties of epoxy resin with Fe-CNTs via large-scale preparation

To further improve the catalytic carbonization efficiency of polymer composites for the formation of compact protective layers in the combustion process, a novel type of Fe-CNTs was prepared in large scale. The Fe-CNTs were used as nanofillers to efficiently improve catalytic carbonization, flame retardancy, and mechanical performances of epoxy resin (EP). With the incorporation of 6 wt% Fe-CNTs, the LOI value of the EP/Fe-CNTs nanocomposites was improved to 35.0 and the UL-94 V-1 rating was passed with an average (t(1) + t(2)) value of 13.3. As compared to pure EP, the PHRR, THR, and TSP of EP/6 wt% Fe-CNTs nanocomposites decreased by 30.7%, 39.1%, and 48.6%, respectively. The significantly improved flame retardancy could be attributed to the compact carbonaceous ceramic layers, which significantly retarded the transfer of heat and combustible gas between the EP nanocomposites and the flame zone. Moreover, the EP/Fe-CNTs nanocomposites exhibited excellent impact and tensile strength performances due to the formation of a strong three-dimensional network structure in the EP matrix.