Study of the synergistic effect of nickel phosphate nanotubes (NiPO-NT) on intumescent flame retardant polypropylene composites

The nickel phosphate nanotubes (NiPO-NT) were synthesized by hydrothermal method, and its structure was characterized. Then NiPO-NT was added to intumescent flame retardants system in polypropylene (PP) matrix for the first time,and the synergistic effect of NiPO-NT with intumescent flame retardants was studied. The results show that only small content of NiPO-NT can obviously improve the flame retardant and thermal properties of intumescent flame retardant PP composite. With the addition of 0.3 % NiPO-NT, the peak heat release rate of intumescent flame retardant PP composite decreases from 374.7 to 255.5 kW m−2, and the limit oxygen index value increases from 29.9 to 33.9. Meanwhile, the maximum mass loss temperature under N2 atmosphere is increased from 408 to 483 °C.