Flame-retardant properties of ethylene-vinyl acetate/oil sludge/ammonium polyphosphate composites

Oil sludge (OS) containing a lot of CaCO3 is a large quantity waste product in the production of oil. OS was used as a material to synthesize the ethylene-vinyl acetate (EVA)/OS/ammonium polyphosphate (APP) composites. The synergistic flame retardant effects between OS and APP in EVA composites were studied using limiting oxygen index (LOI), cone calorimeter test (CCT), scanning electronic microscopy (SEM), smoke density test (SDT), and thermogravimetry-Fourier transform infrared spectrometry. The results showed that the addition of a given amount of APP apparently increased the LOI value. The CCT data indicated that heat release rates (HRR) of EVA/OS/APP composites decreased greatly in comparison with that of EVA and EVA/OS composites. The morphology and structures of residues investigated by SEM gave positive evidence that char layers formed from the EVA/OS/APP composites were more compact than that from the EVA/OS composites. The SDT results showed that APP was helpful to smoke suppression. The TG-FTIR is used to characterize the thermal degradation mechanism of samples and the volatilized products formed on the thermal degradation. (c) 2015 American Institute of Chemical Engineers Environ Prog, 34: 1731-1739, 2015