Flame retardant and mechanical properties of wood powders/PE composites

The influence law of ammonium polyphosphate(APP) and coupling agents on the mechanical properties and flame retardant properties of wood powder/PE composites were studied by mechanical test and limited oxygen index(LOI) test.The experimental results show that the LOI of composites increased from 18.7% to 26.5% when the content of APP flame retardant was 30%,however the mechanical properties decreased.The maleic anhydride graft PP,titanate and silane coupling agent were used to improve mechanical properties of composites and it was implied that titanate and silane coupling agent can improve the mechanical properties of composites obviously.The limited oxygen index of wood powder/PE composites reached 27.5% when the content of titanate was 2%.Thermogravimetric analysis(TGA) shows that APP promoted charring and increased the amounts of char,thus protecting the inner matrix and increased the amount of residual char at higher temperature.The titanate coupling agent further increased the charring formed and rose the thermal stability,so obviously increased the flame retardant of composites.