Abstract: The effect of lanthanum oxide(La2O3)and 4A zeotile (4A) on the flame retardancy and thermal degradation of ethylene-propylene elastomer(MEP)/IFR system was investigated by means of limited oxygen index, scanning electrical microscopy (SEM), thermogravinity analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). It was found that the limited oxygen index values of the composites increased when 1 % compounds were incorporated into it, and 4A had the better synergistic effect with its limited oxygen index reaching to 28.6 %. SEM observed that much more compact char layers were formed when the compounds was added into MEP/IFR system. TGA and FTIR results revealed that the IFR remained more char residue when La2O3 and 4A zeotile were introduced into MEP/IFR, and more polyaromatic spacies, and more P—O—C and P—O—P connected structures were formed.

Key words: ethylene-propylene elastomer, intumescent flame retardant, thermal degradation, charring agent, lanthanum oxide, 4A zeotile