Flame Retardant Polypropylene Matrix Nanocomposites

Polypropylene (PP) matrix nanocomposites reinforced with a variety of nanofillers including magnetic nanoparticles (NPs), carbon nanotubes, magnesium hydroxide, aluminum hydroxide, and silicon dioxide were prepared through in- or ex- situ solution mixing method for flame retardation purpose. In order to improve the filler dispersion quality, polymer-filler interfacial bonding and the flame retardant efficiency, the filler surface pre-treatment/functionalization and the aid of surfactant were used during the preparation of these different PP matrix nanocomposites. The filler surface modification and dispersion were investigated through transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The chemical structures were studied by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and et al. The physicochemical properties of thus prepared nanocomposites including thermal stability, flammability, melting rheological behaviors were studied using thermogravimetric analysis, micro-scale combustion calorimetry, UL-94 vertical burning, limiting oxygen index, and rheometry. The thermal stability and flame retardation mechanism for each composition will be discussed in detail and the advantages as well as the disadvantages for lowering the fire hazards will also be compared.