Flame Retardant Mechanism of a Novel Intumescent Flame Retardant Polypropylene

A novel intumescent flame retardant was incorporated into polypropylene to prepare novel intumescent flame retardant composites (PP/IFR) with good flame retardant properties. The flame retardant mechanism was investigated by means of Laser Raman spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis/infrared spectrometry (TGA-IR), Fourier Transform infrared spectroscopy (FTIR) and Energy Dispersive Spectrometer (EDS). It was found that the IFR could decrease the degradation rate of PP; the formed intumescent char was containing unorganized carbon structure and graphitic structure, and consisting of P, N, O and C elements. FTIR analysis showed that the network with P-O-P and P-O-C were formed. EDS analysis results revealed that some P elements were connected to the polyaromatic rings and could form huge connected network.