Influence of iron oxide green on smoke suppression properties and combustion behavior of intumescent flame retardant epoxy composites

This article mainly studies smoke suppression properties and synergistic flame retardant effects of iron oxide green on intumescent flame retardant epoxy resins (IFREP) using ammonium polyphosphate and pentaerythritol as intumescent flame retardants. Then, the smoke suppression properties of iron oxide green (Fe2O3⋅H2O) on intumescent flame retardant epoxy composites were evaluated using cone calorimeter test (CCT), smoke density test (SDT), scanning electron microscopy (SEM), thermogravimetric analysis-infrared spectrometry. Remarkably, CCT data reveal that a moderate amount of iron oxide green can apparently reduce heat release rate, total heat release, total smoke release, etc. On the other hand, the SDT results show that iron oxide green can catalyze the carbonization of IFREP at low temperature. Here, iron oxide green is considered to be an effective smoke suppression agent and a good synergism with IFR in flame retardant epoxy resins, which can greatly improve the structure of char residue realized by SEM results.