Synergistic flame retardant effect of graphite powder in EVA/LDH composites

Abstract

Red mud (RM) is a large quantity waste product in the production of alumina. There is still no efficient way to deal with it in the world. Using RM as a raw material to synthesise Mg–Al–Fe ternary layered double hydroxide (LDH) is a feasible way to solve this global problem. The synthesised LDH was characterised by X-ray diffraction. The flame retardant and thermal degradation properties of ethylene-vinyl acetate/layered double hydroxide/graphite powder (EVA/LDH/GP) composites have been studied using cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermogravimetry–Fourier transform infrared spectrometry (TG–IR). The CCT data indicate that heat release rates of EVA/LDH/GP composites decrease greatly in comparison with those of EVA, EVA/RM and EVA/LDH composites. The morphological structures of charred residues observed by SEM give positive evidence that the compact char residue layers formed from EVA/LDH/GP composites. The TG–IR is used to characterise volatilised products formed in the thermal degradation process.