Analysis of polymers containing brominated diphenyl ethers as flame retardants after molding under various conditions

McAllister, D.L.; Mazac, Charles J.; Gorsich, Richard D.; Freiberg, M.; Tondeur, Yves

doi:10.1016/0045-6535(90)90309-h

Cited by 17 publications

(5 citation statements)

References 7 publications

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“…The low-temperature combustion results in relatively high emissions of PBDD/Fs. From the results of this study and other research, brominated aromatics can be supposed to be destroyed faster under thermal treatment, resulting in less PBDD/Fs (8,19,20). Emission Factors.…”

Section: Resultsmentioning

confidence: 54%

Inhibition of Polybrominated Dibenzo-p-dioxin and Dibenzofuran Formation from the Pyrolysis of Printed Circuit Boards

Lai¹,

Lee²,

Li³

et al. 2006

Environ. Sci. Technol.

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Waste printed circuit boards containing brominated flame retardants were pyrolyzed in a high-temperature melting system to observe the formation behaviors of polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs). In this study, the results showed that the formation of PBDD/ Fs during pyrolysis can be destroyed under controlled primary combustion conditions. There were two significant factors that influenced the extent of PBDD/F formation. The first factor was temperature. The results showed that, both the total PBDD/F content in the bottom ash and the total PBDD/F emission factor from the flue gas decrease by approximately 50% with an increase of the pyrolysis temperature from 850 to 1200 degrees C. The second factor was the addition of CaO. The possible mechanism involves the reaction between CaO and HBr to form the solid-phase product CaBr2. Thus, the addition of CaO is effective in adsorbing HBr and results in the inhibition of PBDD/F synthesis by more than 90% and further prevents the acid gases (HCl and HBr) that corrode the equipment. In conclusion, due to the persistence and toxicity of PBDD/Fs, a combined regulation for controlling both PCDD/Fs and PBDD/Fs is of great importance for environmental protection issues.

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Section: Resultsmentioning

confidence: 54%

Inhibition of Polybrominated Dibenzo-p-dioxin and Dibenzofuran Formation from the Pyrolysis of Printed Circuit Boards

Lai¹,

Lee²,

Li³

et al. 2006

Environ. Sci. Technol.

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“…However, even though a vast literature is available on the mechanisms of formation of chlorinated polyaromatic structures, less attention has been devoted to the brominated homologues. The studies performed in the past 15 years have mainly concerned the formation of polybrominated dibenzofurans (PBDFs) and dibenzodioxins (PBDDs) in the thermal degradation of polybrominated diphenyl ether flame retardants. − …”

Section: Introductionmentioning

confidence: 99%

Thermal Stability and Decomposition Products of Hexabromocyclododecane

Barontini¹,

Cozzani²,

Petarca³

2001

Ind. Eng. Chem. Res.

134

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The thermal stability and decomposition products of hexabromocyclododecane (HBCD), a widely used aliphatic brominated flame retardant, were investigated. HBCD thermal degradation was carried out in nitrogen and in air at moderate heating rates (10 °C/min) using thermogravimetric analyzers and a laboratory-scale fixed-bed reactor. The identification of decomposition products was based mainly on FTIR and gas-chromatographic/mass-spectrometric techniques. Quantitative data on hydrogen bromide formation and on the bromine distribution among the different product fractions were obtained. For the experimental conditions used in this study, about 75 wt % of the bromine is released as HBr, and 25 wt % is involved in the formation of high-molecular-weight bromo-organic compounds. The main pathways of HBCD thermal degradation were assessed, and a global mechanism for HBCD decomposition was proposed.

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“…The flow curve in Figure 5 shows the viscosity (log 77) of HIPS/Br 10DPO/Sb2O3 as a function of shear rate (log 7). In the range 100 < 7 < 1000 it follows readily that the power law index n is given by n = d(log 77)/d(log 7) + 1 (10) For HIPS/Br 10DPO/Sb203 the power law index n is 0.26.…”

Section: Resultsmentioning

confidence: 98%

“…The formation of PBDFs occurs during polymer degradation (T = 350-400 °C) (8). Recently, formation of PBDFs during compounding of polymers with polybrominated flame retardants has been shown (9)(10)(11). Brenner et al (12) measured PBDFs in the workplace area during compounding of poly(butylene terephthalate) (PBTP)/glass fiber/Br 10DPO/Sb203 polymer blends.…”

Section: Introductionmentioning

confidence: 99%

“…We investigated the effect of mineral surfaces in the presence of dissolved sulfide on the transformation rate of carbon tetrachloride. CC14 was chosen as the compound of interest because it is a contaminant which is frequently found in groundwater, it is a suspected human carcinogen (9) , it causes ozone depletion, and it is a greenhouse gas (10) . Laboratory studies were conducted to identify and quantify the environmental parameters that govern the transformation rate of CC14 in a heterogeneous aqueous environment containing sulfide and sheet silicates (biotite and vermiculite).…”

Section: Introductionmentioning

confidence: 99%

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Formation of polybrominated dibenzofurans during extrusion of high-impact polystyrene/decabromodiphenyl ether/antimony(III) oxide

Luijk¹,

Govers²,

Nelissen³

1992

Environ. Sci. Technol.

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Polybrominated dibenzofurans (PBDFs) are formed during extrusion of high-impact polystyrene (HIPS) containing the flame retardant system decabromodiphenyl ether/antimony(III) oxide (Br,,,DPO/Sb203). The process of formation of PBDFs was examined at an extrusion temperature of 275 "C. To get a better understanding of processes taking place in the polymer melt during extrusion) the thermal stability of polystyrene chains was also examined. It was found that the flame retardant system Br&PO/Sb203 shows a stabilizing activity toward thermal degradation of polystyrene chains. Temperature development during extrusion processing of HIPS/ Br1&PO/Sb2O3, simulated in a computer model, supports a mechanism of formation of PBDFs which is initiated by thermal degradation of polystyrene. Polystyrene degradation products, i.e., (po1y)styrene radicals, are stabilized by radical scavenging properties of the flame retardant decabromodiphenyl ether (Br&PO). Debromination of Brl&PO is combined with a ring-closure reaction forming PBDFs. It seems inevitable that PBDFs are formed during extrusion of polybrominated diphenyl ethers in addition polymers such as polystyrene. A tentative quantification of the yield of PBDFs in HIPS/BrloDPO/Sb203 by RP-HPLC showed an increase from 1.5 to 9 ppm for heptabromodibenzofuran and from 4.5 to 45 ppm for octabromodibenzofuran after four extrusion cycles.

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Analysis of polymers containing brominated diphenyl ethers as flame retardants after molding under various conditions

Cited by 17 publications

References 7 publications

Inhibition of Polybrominated Dibenzo-p-dioxin and Dibenzofuran Formation from the Pyrolysis of Printed Circuit Boards

Inhibition of Polybrominated Dibenzo-p-dioxin and Dibenzofuran Formation from the Pyrolysis of Printed Circuit Boards

Thermal Stability and Decomposition Products of Hexabromocyclododecane

Formation of polybrominated dibenzofurans during extrusion of high-impact polystyrene/decabromodiphenyl ether/antimony(III) oxide

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