Study on flame retardancy of polyethylene/wood composite

As synergistic agent,nano-silica(SiO2) and ammonium chloride(NH4Cl) with ammonium polyphosphate(APP) are used as flame retardant to prepare fire retardant polyethylene/wood composite(WPC).The thermal property,fire retardancy,flame retardant mechanism,and the structure of the char residue of the fire retardant WPC are analyzed by TGA,LOI,FTIR and SEM.The results show that the LOI increases to 29.4% with the addition of flame retardants of APP,SiO2 and NH4Cl with the mass ratio of 9.8 ∶ 1.1 ∶ 1.6.The char residue of fire retardant WPC improves by 170% at 800 ℃,and its chemical composition changes after fired,at the same time,somescalelike crystals can be seen on the surface of the char residue of fire retardant WPC.