The synergistic smoke suppression effect of ferric oxide on flame retardant wood-polyurethane composites
Wood flour-polyurethane composites (WPC) with ammonium polyphosphate (APP) and ferric oxide (Fe2O3) were prepared to research the cooperative influence of smoke suppression and fire resistance. By the methods of cone calorimeter test (CCT), smoke density test (SDT), thermogravimetric analysis (TG), limiting oxygen index (LOI), field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). Remarkably, Fe2O3 has significant improvement on heat release rate (HRR), total heat release (THR), smoke factor (SF), and total smoke release (TSR) of the APP/WPC.SDT implied that Fe2O3 played a positive role during burning and there is a synergistic effect of smoke suppressing for Fe2O3 on APP/WPC. The LOI results showed that compared with samples without flame retardant, adding Fe2O3 improved the LOI value of WPC. TG indicated that Fe2O3 and APP played an effective role in the course of thermal degradation of WPC. And the SEM and FTIR showed that Fe2O3 and APP played a role in ameliorating the residual carbon structure.