The flame retardant and smoke suppression effect of fullerene by trapping radicals in decabromodiphenyl oxide/Sb2O3 flame-retarded high density polyethylene

To improve the large release of smoke and heat for brominated flame retardants (BFRs) in fire hazard, fullerene (C-60) had been introduced in high density polyethylene (HDPE)/bromine flame retardant (Deca/Sb2O3, BFR in short) system in this study. The effects of C-60 on the thermal properties, flame retardant properties, rheological behaviors, and smoke release behaviors in HDPE/BFR blends were researched. During polymer thermal degradation, C-60 and BFR exhibited the trapping radical ability in condensed phase and gaseous phase, respectively. The intergrated effects of C-60 and BFR on the thermal stability and flammability of HDPE were studied by thermo-gravimetry and cone calorimeter. It was indicated that the introduction of C-60 improved the thermal and thermo-oxidative stability of HDPE/BFR blends. A remarkable advantage of adding C-60 was to reduce the peak heat release rate and the average specific extinction area, especially at higher concentration of C-60. The analysis of rheological behaviors and pyrolysis products revealed that C-60 can capture alkyl radicals, chain radicals, and bromine radicals in the condensed phase, which was in favor of terminating the thermo-oxidative decomposition and inhibiting the heat and smoke release of HDPE/BFR blends during combustion.