title: TG-MS investigation of brominated products from the degradation of brominated flame retardants in high-impact polystyrene.
abstract: The thermal degradation of flame retardant containing high-impact polystyrene (HIPS-Br), one of the most commonly employed plastics in electric and electronic appliances, was examined by thermogravimetry coupled with mass spectroscopy (TG-MS) in order to understand the threat that is posed by the release of hazardous brominated compounds. The HIPS samples contained decabromodiphenylether (DPE) and decabromodibenzyl (DDB) as the flame retardants as well as Sb2O3 as the synergist. The largest number of brominated compounds was obtained in the presence of DPE and Sb2O3 and DDB without Sb2O3. From the degradation of DPE, brominated benzenes, phenols, diphenylethers, and dibenzofurans were identified, and from the degradation of DDB, brominated benzenes, dibenzyls, and phenanthrenes were formed. The interaction between the flame retardant and the polymer matrix resulted in α-bromoethylbenzene. The formation of brominated dibenzodioxins was not observed, probably, due to the low phenol concentration in the polymer melt. No other report has, to our knowledge, ever reported on the formation of brominated phenanthrenes from flame retardants. Because they share similar steric features, it may well be that brominated phenanthrenes are similar in their carcinogen and mutagen potential to dibenzofurans and dibenzodioxins. A plausible mechanism for the formation of the observed compounds is presented, and the role of the synergist is considered.
authors.affiliation: Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 6-6-11, Aoba-ku Sendai 980-8579, Japan. grause@env.che.tohoku.ac.jp
authors.forename: Guido
authors.initials: G
authors.lastname: Grause
authors.forename: Daiki
authors.initials: D
authors.lastname: Karakita
authors.forename: Jun
authors.initials: J
authors.lastname: Ishibashi
authors.forename: Tomohito
authors.initials: T
authors.lastname: Kameda
authors.forename: Thallada
authors.initials: T
authors.lastname: Bhaskar
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yoshioka
mesh_terms: D000965:Antimony / Q000737:chemistry; D005411:Flame Retardants / Q000032:analysis*; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry; D013058:Mass Spectrometry; D010087:Oxides / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D010087:Oxides; D011137:Polystyrenes; C091696:antimony oxide; D000965:Antimony; C010902:decabromobiphenyl ether