Thermal degradation of flame-retarded polyethylene/magnesium hydroxide/poly(ethylene-co-propylene) elastomer composites

Magnesium hydroxide-based halogen-free flame retarded linear low-density polyethylene (LLDPE) composites containing poly(ethylene-co-propylene) (EP) elastomer were prepared by a melt process and subsequently vulcanized thermally. The thermal degradation of the composites was studied using thermogravimetric (TG) analysis and real-time Fourier transform infrared (RT-FTIR) spectroscopy. The combustion residues from the composites were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results from TG and RT-FTIR tests show that the incorporation of a suitable amount of the elastomer into polyethylene/magnesium hydroxide composites after vulcanization increases the thermal stability. A graphite-like char was found for the composites with EP elastomer, from Raman spectroscopy studies. XPS results indicate that there are several forms of carbon present in the combustion residues of the composites with EP elastomer, compared with only one form of carbon in the residues of the composites without the elastomer. (C) 2003 Society of Chemical Industry.