Degradation Mechanism of Decabromodiphenyl Ether: Reaction with Reactive Radicals and Formation Chemistry Of Polybrominated Dibenzo-P-Dioxins and Dibenzofurans DOI

Yang Long,

Liming Tai,

Shi Fang Yan

et al.

Published: Jan. 1, 2025

Despite decabromodiphenyl ether (BDE-209) has been banned from production and use as a brominated flame retardant, its threat to human ecological environment cannot still be ignored. Nevertheless, the mechanism of BDE-209 initiated by reactive radicals in thermochemical decomposition process remains unknown. The density functional theory (DFT) method is used study behavior with radical reactions formation polybrominated dibenzo-p-dioxins dibenzofurans (PBDD/Fs). results show that not prone self-decomposition due high BDEs (249.6 ~ 281.4 kJ/mol) HOMO-LUMO energy gap (7.10 eV). reaction three active free radicals, including •H, Br•, •OH, usually variety hypobromated products or important intermediates at low barriers (52.9, 54.3, 50.4 kJ/mol). OH-addition OH-abstraction form octabromodibenzo-p-dioxin, which further debrominated PBDDs. Ortho-phenyl-type generated eliminating ortho-Br crucial precursor for PBDD/Fs. most favorable pathway subsequent degradation ortho-phenyl-type IM10 → TS38 IM13. participation polymer materials increased toxic reason formed chain scission can easily extract atom BDE-209, thereby promoting (ortho-phenyl radical) induced explored help control substances during thermal treatment.

Language: Английский

Degradation Mechanism of Decabromodiphenyl Ether: Reaction with Reactive Radicals and Formation Chemistry Of Polybrominated Dibenzo-P-Dioxins and Dibenzofurans DOI

Yang Long,

Liming Tai,

Shi Fang Yan

et al.

Published: Jan. 1, 2025

Despite decabromodiphenyl ether (BDE-209) has been banned from production and use as a brominated flame retardant, its threat to human ecological environment cannot still be ignored. Nevertheless, the mechanism of BDE-209 initiated by reactive radicals in thermochemical decomposition process remains unknown. The density functional theory (DFT) method is used study behavior with radical reactions formation polybrominated dibenzo-p-dioxins dibenzofurans (PBDD/Fs). results show that not prone self-decomposition due high BDEs (249.6 ~ 281.4 kJ/mol) HOMO-LUMO energy gap (7.10 eV). reaction three active free radicals, including •H, Br•, •OH, usually variety hypobromated products or important intermediates at low barriers (52.9, 54.3, 50.4 kJ/mol). OH-addition OH-abstraction form octabromodibenzo-p-dioxin, which further debrominated PBDDs. Ortho-phenyl-type generated eliminating ortho-Br crucial precursor for PBDD/Fs. most favorable pathway subsequent degradation ortho-phenyl-type IM10 → TS38 IM13. participation polymer materials increased toxic reason formed chain scission can easily extract atom BDE-209, thereby promoting (ortho-phenyl radical) induced explored help control substances during thermal treatment.

Language: Английский

Citations

0