Study on the Synergistic Effect of EG with APP in Flame Retardant Polyethylene

PE HD composites were prepared with expandable graphite(EG) and ammonium polyphosphate (APP) as the compound flame retardant.Thermal analysis showed that the incorporation of APP/EG reinforced the thermal stability of the composite; alleviated its degradation; increased its char residue.The limiting oxygen index indicated that APP and EG had good synergistic effect.SEM exhibited that a continuous and compact char layer formed in the system with the addition of APP and EG.It was also noted that APP and EG had less impact on the system than other flame retardants.