Tetrabromobisphenol additive

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. 

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... 

Most circuit boards are FR-4 boards that meet standards for fire safety by the use of brominated epoxy resins in which the reactive flame-retardant tetrabromobisphenol A (TBBPA) forms part of the polymeric backbone of the resin. Alternative flame-retardant materials are used in only 3-5 per cent of the FR-4 boards, but additional alternative flame-retardant materials are also imder development. Little information exists concerning the potential environmental and human health impacts of the materials which are being developed as alternatives to those used today that are based on brominated epoxy resins. 

Various additives show considerable extraction resistance, such as impact modifiers (polyacrylates and polyblends PVC/EVA, PVC/ABS, etc.), highpolymeric processing aids (PMMA-based), elastomers as high-MW plasticisers, reactive flame retardants (e.g. tetrabromobisphenol-A, tetrabromophthalic anhydride, tetrabromophthalate diol, dibromostyrene). Direct measurement of additives by UV and IR spectroscopy of moulded films is particularly useful in analysing for additives that are difficult to extract, although in such cases the calibration of standards may present a problem and interferences from other additives are possible. 

Examples of additives to which either or both of these reaction sequences could apply are decabromodipheny1 oxide (DBDPO), tetrabromobisphenol-A (TBBPA) and the chlorinated cyclopentadiene adducts. 

Driffield M, Harmer N, Bradley E, Fernandes AR, Rose M, Mortimer D, Dicks P (2008) Determination of brominated flame retardants in food by LC-MS/MS diastereoisomer-specific hexabromocyclododecane and tetrabromobisphenol A. Food Addit Contamin... 

Among the emerging pollutants of industrial origin, Bisphenol A [2,2 bis(4-hydroxydiphenyl)pro-pane] (BPA) has special relevance since it was one of the first chemicals discovered to mimic estrogens as endocrine disrupters.147 This compound was first reported by Dianin in 1891.1411 BPA is produced in large quantities worldwide, mainly for the preparation of polycarbonates, epoxy resins, and unsaturated polyester-styrene resins.149 The final products are used in many ways, such as coatings on cans, powder paints, additives in thermal paper, in dental composite fillings, and even as antioxidants in plasticizers or polymerization inhibitors in polyvinyl chloride (PVC). To a minor extent, BPA is also used as precursor for flame retardants such as tetrabromobisphenol A or tetrabromobisphenol-S-bis(2,3-dibromopropyl) ether.150 This substance can enter the environment... 

Tetrabromobisphenol A epoxy resins are available as viscous liquids with several molecular weight ranges. As the bromine content increases, the flame resistance increases but the viscosity of the resin generally increases as well. They are primarily used as an additive in formulations producing epoxy laminates and adhesives that require improved resistance to ignition. 

Bromine compounds are also used as fire retardants. These compounds are about twice as effective as chlorine compounds on a weight basis, so that significantly lower concentrations are needed. However, bromine compounds are higher in cost than chlorinated compounds and are generally less stable under exposure to heat and light (29). Those compounds containing aromatic bromine are significantly more stable to heat and hydrolysis than the aliphatic type. Examples are decabromodiphenyl oxide (DBDPO), tetrabromobisphenol and tetrabromobisphenol A. A pentabromodiphenyl oxide blend is available for urethane foams and polyesters (34). Aliphatic bromine-type additives are used as flame retardants in plastic foams (polyurethane and polystyrene (33). 

Tetrabromobisphenol A, a brominated analog of Bisphenol A, is an important nonflammable additive in the production of synthetic resins, polycarbonates and plastics, used in the manufacture of computer and electronic housings, laminated electronic circuit boards, carpets, upholstery and many other consumer goods . Tetrabromobisphenol A is used as a flame retardant to a much larger extent than its chlorinated analog tetrachloro-bisphenol... 

For quality control reasons, rapid screening methods are needed to identify the volatiles in polymeric materials collected for recycling. HS-SPME-GC-MS was shown to be a fast and sensitive method to screen for brominated flame retardants in recycled polyamide materials [78]. HS-SPME effectively extracted several brominated compounds, all possible degradation products from the common flame-retardant Tetrabromobisphenol A from recycled polyamide 6.6. Furthermore, the high extraction capacity of the PDMS/DVB stationary phase towards aromatic compounds was demonstrated, as the HS-SPME-GC-MS method allowed the extraction and iden-tiflcation of brominated benzenes, from a complex matrix only containing trace amounts of analytes. In addition, degradation products from an antioxidant, a hindered phenol, were extracted. Figure 14 shows a typical chro-... 

In order to provide the required flame retardancy to the molding compound, an encapsulated formulation usually contains brominated resins and antimony oxide. The brominated resins used in the encapsulated formulation are mainly tetrabromobisphenol A (TBBA) based epoxy resin or brominated epoxy novolac. These bromine-containing additives were reported to cause bond degradation at high temperature through accelerated void formation in the gold-aluminum intermetallic phases (1-4). 

Brominated flame retardants (BFRs) are a structurally diverse group of compounds including aromatics, cyclic aliphatics, phenolic derivatives, ahphatics, and phthahc anhydride derivatives (Figure 31.3). The most common BFRs are tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDE), hexabromocyclododecane (HBCD), and polybrominated biphenyls (PBB). The primary use of TBBPA is as reactive additive in epoxy resin circuit boards, while decabromodiphenyloxide (DBDO) is primarily used in high impact polystyrene for electronic enclosures. PBDEs are typically used as the additive type of flame retardant in high impact polystyrene, acrylonitrile butadiene styrene, flexible polyurethane foam, textile coatings, wire and cable insulation and electrical connectors. 

Known for many years, epoxy oligomers made from tetrabromobisphenol A are still used as the flame retardant in polycarbonates because they minimally affect the heat distortion temperature and even show a positive effect on impact strength. About 6—9 wt% of the epoxy oKgomer is required for achieving V-0 rating and a thermotropic liquid crystal polyester helps to improve melt flow, so that thin-waUed parts can be molded [38]. Antimony trioxide is not normally used in combination with halogen-containing additives in PC, because it causes loss of clarity. 

Brontinated PS is combined with antimony trioxide as a flame retardant. In addition, brontinated poly(phenylene ether) has been used. Other flame retardants are tetrabromocyclooctane, tetrabromovinylcyclo-hexene, or bis-(allyl ether) tetrabromobisphenol A. For the latter flame retardants, dicumyl peroxide is added as a synergist and the additives are used together with blowing agents. 

Examination of flame-retarding additives was done by Heeren et al. using a direct temperature controlled pyrolysis external ion source and a 7 T FTICR. Samples were taken from common household appliances such as TV set housings, computer casings, and others and were pulverized to powder form. Direct heating of the filament probe with dried sample produced spectra with two distinct regions, corresponding to evaporation of nonbonded additives and pyrolysis of the polymer matrix. The xmknown polymer blends were foxmd to contain brominated biphenyls, brominated diphenyl ethers, tetrabromoBisphenol-A and its butylated isomers, polystyrene, and antimony oxides. 

Tried-and-tested flame retardant systems based on bromine compounds will continue to be used, with just a few exceptions, on account of their outstanding price-to-performance ratio. This is clear from printed circuits, where halogen-free reactive and additive FR systems are not able to displace the FR4 laminates based on tetrabromobisphenol-A (TBBA). Such is the case in Europe, at least. The situation could prove to be different in Asia, since the giants in the sector, such as Sony, have committed themselves to halogen-free printed circuits. In Europe and Asia, iimovations in flame retardant plastics continue to be in the field of halogen-fi ee systems. 

Great Lakes have found that tetrabromobisphenol A bis (2,3-dibromopropyl ether) is an effective flame retardant for PP homo- and copol5miers plus talc filled systems. It provides for UL94 V-2 rating and Glow Wire 850-960 °C requirements with additions of antimony trioxide in the compounded systems. 

Flame Retardants. Flame retardance can be built into the epoxy resin by use of tetrabromobisphenol A or anhydride curing agents containing phosphorus or halogen. It can also be helped by nonreactive additives such as alumina trihydrate or organo-halogens + antimony oxide. 

The most effective fire-retardant polymeric materials are halogen-based polymers (e.g., PVC, chlorinated PVC, polyvinylidene fluoride (PVDF)) and additives (e.g., chlorinated paraffins (CPs), tetrabromobisphenol A (TBBA)). However, the improvement in fire performance depends on the type of fire tests, that is, the application. 

Brominated hydrocarbons. Brominated hydrocarbons represent the highest dollar volume among all flame retardants used worldwide. The major additive types are decabromodiphenyl oxide (DBDPO) and derivatives of tetrabromobisphenol A(TBA). The major reactive type is TBA itself. Significant amounts of TBA are also used to make additive types. Typically, brominated compoimds are used with a synergist... 

Flame retardants prevent polymeric materials from supporting a flame, sufficiently to meet the requirements of standards. They are used either as additives mixed with the polymer or as coreactants, in which the reactive flame retardant is covalently bonded with the polymer. Polybrominated diphenyl ethers and organophosphate esters are both used as flame retardants as well as having plasticising properties. Tetrabromobisphenol A can be used either as an additive or as a reactive flame retardant [20]. 

Cyanuric chloride (0.05 mole), tetrabromobisphenol A (TBA) (0.04 mole) and TBP (0.07 mole) were dissolved in a solvent (lOOg) and the whole mixture was kept at given temperatures (usually 0-5 C). To this mixture was added a solution of sodiiam hydroxide (0.15 mole) in water (6.0g) drop by drop. After the addition was completed, the mixture was kept stirred for 1/2 hr, then heated to bring refluxing for 3 hrs and kept stirred at that temperature for another 3 hrs. The whole mixture was then allowed to cool down to room temperature and poured into large excess of methanol. After removing methanol-insoluble materials, the desired product was obtained by drying in vacuo at 60°C. 

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