Synergistic effects between iron-graphene and ammonium polyphosphate in flame-retardant thermoplastic polyurethane

This article mainly studies synergistic flame-retardant effects of iron-graphene (IG) and ammonium polyphosphate (APP) in thermoplastic polyurethane (TPU). A high concentration of TPU/IG masterbatch was prepared by solution-blending method, and the TPU/APP/IG composites were prepared by melt-blending method. Then, the synergistic effects between iron-graphene and ammonium polyphosphate in flame-retardant TPU were investigated by limiting oxygen index (LOI), cone calorimeter test, and thermogravimetric/Fourier infrared spectrum (TG-IR), respectively. Remarkably, the combination of 0.25 mass% IG and 9.75 mass% APP can make the LOI value increase by 38.3 %, HRR value decrease by 92.8 %, and SPR value decrease by 72.8 %, etc. TG and TG-IR data reveal that APP and IG improve the thermal stability of samples at high temperature and reduce the production of some toxic gases.