Flame-retardant effect of montmorillonite intercalation iron compounds in polypropylene/aluminum hydroxide composites system

Montmorillonite possesses nanometer size effect and layer blocking effect, and iron compounds have significant catalytic carbonization performance. Based on these above, the new montmorillonite intercalation iron compounds (MIICs) are designed and synthesized. The MIIC is a typical lamellar compound that holds the homogeneity crystal structure and the adjustable component. The MIIC was modified by cetyltrimethylammonium bromide and obtained organic MIIC (OMIIC). Polypropylene (PP)/aluminum hydroxide (ATH)/OMIIC nanocomposites were prepared via melting intercalation. The structures of PP/ATH/OMIIC nanocomposites were studied by XRD and transmission electron microscope, which indicate that OMIIC disperses well in PP composites, and PP/ATH/OMIIC nanocomposites have the exfoliated and intercalated structures. The combustion tests show that the small amount of OMIIC in PP/ATH composites can apparently favor UL94 test and suppress dripping phenomenon. The cone calorimeter tests indicate that the heat release rate is significantly reduced by the formation of nanocomposites, and the THR of the PP/ATH/OMIIC nanocomposites was decreased in comparison with that of the PP/ATH nanocomposites, which should be attributed to the formation of compact protective char layer.