Synthesis of brominated acenaphthylenes and their flame-retardant effects on ethylene–propylene–diene terpolymer

Authors

  • Yohsuke Morita,

    1. Japan Atomic Energy Research Institute, Takasaki Radiation Chemistry Research Establishment, Watanuki-Machi, Takasaki, Gunma, Japan 370-12
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  • Miyuki Hagiwara

    1. Japan Atomic Energy Research Institute, Takasaki Radiation Chemistry Research Establishment, Watanuki-Machi, Takasaki, Gunma, Japan 370-12
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Abstract

Bromoacenaphthylenes and their condensates as flame-retardant reagents were synthesized by bromination of acenaphthylene using ZnCl2[BOND]CF3COOH or FeCl3 as catalysts and subsequent dehydrobromination. The chief components were identified as bromoacenaphthylene monomers when ZnCl2[BOND]CF3COOH were used, and as their condensates (mostly trimers) in the case of FeCl3. Their performance as flame-retardant reagents for ethylene–propylene–diene terpolymer (EPDM) was evaluated by measuring the oxygen index of finished compounds, and flammability by a vertical flammability test based on UL-94-VO. Both the monomers and the condensates demonstrated high flame-retardant effectiveness. The high efficiency was attributed to their excellent dispersity in the base polymer and their characteristic thermal decomposition behavior. In TGA, they decomposed in a very wide range of temprature (ca.200–560°C), which covers the decomposition range of EPDM. This was attributed to the existence of bromines of different thermal stabilities in one molecule.

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