Effects of Zinc Phytate on Flame Retardancy and Thermal Degradation Behaviors of Intumescent Flame-retardant Polypropylene

In this paper, zinc phytate was prepared and used as a synergist in intumescent flame-retarded polypropylene composites. The results showed that the polypropylene composites with 17 wt% intumescent flame retardant and 2 wt% zinc phytate have a limiting oxygen index 29.2 and achieve the UL-94 V-0 rating. Moreover, the peak heat release rate of the polypropylene composites decreases from 374 to 275 kW/m2. Real-time Fourier-transform infrared spectroscopy showed that the zinc phytate delays the emission of carbon dioxide indicating that zinc phytate slows the degradation of polypropylene which regulates the suitability of intumescent flame-retardant system in polypropylene.