2,2/6,6/-Tetrabromobisphenol

Brominated Additive Flame Retardants. Additive flame retardants are those that do not react in the appHcation designated. There are a few compounds that can be used as an additive in one appHcation and as a reactive in another. Tetrabromobisphenol A [79-94-7] (TBBPA) is the most notable example. Tables 5 and 6 Hst the properties of most commercially available bromine-containing additive flame retardants. 

TetrabromobisphenoIA. Tetrabromobisphenol A [79-94-7] (TBBPA) is the largest volume bromiaated flame retardant. TBBPA is prepared by bromination of bisphenol A under a variety of conditions. When the bromination is carried out ia methanol, methyl bromide [74-80-9] is produced as a coproduct (37). If hydrogen peroxide is used to oxidize the hydrogen bromide [10035-10-6] HBr, produced back to bromine, methyl bromide is not coproduced (38). TBBPA is used both as an additive and as a reactive flame retardant. It is used as an additive primarily ia ABS systems, la ABS, TBBPA is probably the largest volume flame retardant used, and because of its relatively low cost is the most cost-effective flame retardant. In ABS it provides high flow and good impact properties. These benefits come at the expense of distortion temperature under load (DTUL) (39). DTUL is a measure of the use temperature of a polymer. TBBPA is more uv stable than decabrom and uv stable ABS resias based oa TBBPA are produced commercially. 

Brominated C rbon te Oligomers. There are two commercial brominated carbonate oligomer (BrCO) products. Both are prepared from tetrabromobisphenol A and phosgene. One has phenoxy end caps [28906-13-0] and the other trihromophenoxy [71342-77-3] end caps. These are used primarily in PBT and polycarbonate/acrylonittile—butadiene—styrene (PC/ABS) blends. 

Halogenated intermediates, dibromoneopentyl glycol [3296-90-0] (DBNPG), and alkoxylated derivatives of tetrabromobisphenol A are used extensively in flame-retardant apphcations. Similar properties can be derived from halogenated dibasic acids, chlorendic anhydride [115-27-5] (CAN), and tetrabromophthahc anhydride [632-79-1] (TBPA). Processes can be used to produce brominated products by the in situ bromination of polymers derived from tetrahydrophthahc anhydride. 

The preparation of flame-retardant epoxy resins is accompanied by inclusion of tetrabromobisphenol A [79-94-7] in the advancement process (see Flame retardants). Products containing ca 20 wt % Br are extensively employed in the printed circuit board industry. 

Liquid resins containing bromine (ca 49 wt %) can also be prepared directly from tetrabromobisphenol A and epichlorohydrin and are used for critical appHcations where a high degree of flame retardancy is required. 

Monobromobenzene 1, 1,2-dibromobenzene 2, 1,3 dibromobenzene 2, 1,4-dibromobenzene 4, hexabromobenzene 5 and tetrabromobisphenol A 6 are used as plasticizers, flame retardants or intermediates for various syntheses. Except for 1, a limited number of studies regarding the toxicity and metabolism of above compounds has been performed. This report presents some studies on the hepatotoxic action (necrotic and porphyrogenic effects) of these compounds. 

The brominated organic compounds are used as either additive (e.g. decabromodiphenyl, hexabromobenzene, pentabromotoluene), or reactive flame retardants (e.g. tetrabromobisphenol-A, tri- and pentabromophenols). The major... 

The purpose of this study was to compare hepatotoxic effects of monobromo-benzene, 3 dibromobenzene isomers, hexabromobenzene and tetrabromobisphenol A with special attention paid to the dynamics of changes of selected indicators of liver necrosis during acute poisoning. 

The activity of y-GT as well as the level of TG and GSH after repeated administration of the studied compounds did not change. The increase of GPT activity in rats serum was observed only after 3 doses of tetrabromobisphenol A 6 (1000 mg/kg). 

In the present study the investigations on the liver impairment in experimental animals, caused by bromobenzene, dibromobenzenes, hexabromobenzene and tetrabromobisphenol were described. 

Ronen Z, A Abeliovich (2000) Anaerobic-aerobic process for microbial degradation of tetrabromobisphenol-A. Appl Environ Microbiol 66 2372-2377. 

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