Effects of thermal aging on degradation mechanism of flame retardant‐filled ethylene–propylene–diene termonomer compounds

Abstract

ABSTRACTEthylene–propylene–diene termonomer (EPDM) compounds filled with halogenated (Br and Cl) flame retardants (FRs) and Sb2O3 were prepared via melt mixing, and their thermal stability, weight loss, and elemental composition were investigated as a function of aging conditions (temperature: 120–380°C, period: ∼100 h, and atmosphere: nitrogen and air). The thermal aging was done with thermogravimetic analysis under both isothermal and nonisothermal conditions and a convection oven. Scanning electron microscopy–energy dispersive spectroscopy was used to study the surface morphology and elemental composition of the thermally aged FRs‐filled EPDM compounds. For a better precision of compositional analysis, a laser‐induced breakdown spectroscopy (LIBS) was employed in this study. The thermal degradation behavior of EPDM compounds containing halogenated FRs was strongly dependent on the aging atmosphere (N2 or air) and type of FRs. The weight loss of the EPDM compounds during thermal aging was found to be quite small in the temperature ranges below 190°C, while it was noticeable above the temperature. The LIBS technique can be an effective and promising analysis tools for analyzing the elemental components in a bulk rubber compound. Two possible mechanisms were proposed for the thermal degradation of the EPDM compounds containing brominated FR and Sb2O3. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41324.