Improvement of the Thermal Behaviour of Epoxy/Fe Nanoparticle Composites by the Addition of Flame Retardants

Abstract The use of nanoparticles as fillers is considered a promising direction for improving the thermal stability and reducing the flammability of polymers. However, nanoparticles can provide a sufficient flame retardant effect only in combination with other flame retardants. In this study, to improve the thermal stability of epoxy composites, the Fe-nanoparticles were added in the epoxy resin alone and in combination with aluminium trihydroxide (ATH) and melamine polyphosphate (MPP) chemicals. Thermal characterization of the epoxy composites was carried out by using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) under air atmosphere. The results of thermal analysis revealed that the separate addition of Fe-nanoparticles decreased the maximum degradation rate while the combination of the Fe-nanoparticles with the ATH and MPP increased the midpoint temperature at which a loss of 50 wt% of the mass of the epoxy specimens, as well as to a decrease in the maximum decomposition rate of the epoxy composites when heated. The limiting oxygen index (LOI) value of the epoxy composite increased from 19 to 28 with the addition of 15% ATH, 27% with the addition of 15% MPP, and 23% with the addition of Fe-nanoparticles. In conclusion, the MPP showed better performance than the AHT in improving the thermal stability and flame retardancy of epoxy composites.