Bromine, in flame retardants

A Novel System for the Application of Bromine in Flame-Retarding Polymers... 

Lewin, M. Guttmann, H. Sarsour, N. In A novel system for the application of bromine in flame retarding polymers, Fire and Polymers. 1991. 

TABLE 3 Use of Organo-bromine in flame-retarded formulations... 

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. 

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. 

Halogenated intermediates based on chlorendic anhydride and alkoxylated, brominated bisphenol are quite stable and are used extensively in flame-retarded high temperature compositions, but brominated aUcychcs, such as dibromotetrahydrophthahc resin, are rapidly dehydrohalogenated at lower temperatures. 

An important use of bromine compounds is in the production of flame retardants (qv). These are of the additive-type, which is physically blended into polymers, and the reactive-type, which chemically reacts during the formation of the polymer. Bromine compounds are also used in fire extinguishers. Brominated polymers are used in flame retardant appHcations and bromine-containing epoxy sealants are used in semiconductor devices (see... 

Flame Retardants. Bromine compounds make up an important segment of the market for flame retardants used in polymers. Additive flame retardants are added to polymers during processing reactive flame retardants react chemically to become part of the polymer chain itself. In addition to the compounds Hsted in Table 3, a number of proprietary mixtures and phosphoms—bromine-containing flame retardants are also sold (see Elame RETARDANTS, HALOGENATED, FLAAffi RETARDANTS). 

Principles and Characteristics Combustion analysis is used primarily to determine C, H, N, O, S, P, and halogens in a variety of organic and inorganic materials (gas, liquid or solid) at trace to per cent level, e.g. for the determination of organic-bound halogens in epoxy moulding resins, halogenated hydrocarbons, brominated resins, phosphorous in flame-retardant materials, etc. Sample quantities are dependent upon the concentration level of the analyte. A precise assay can usually be obtained with a few mg of material. Combustions are performed under controlled conditions, usually in the presence of catalysts. Oxidative combustions are most common. The element of interest is converted into a reaction product, which is then determined by techniques such as GC, IC, ion-selective electrode, titrime-try, or colorimetric measurement. Various combustion techniques are commonly used. 

As many bromine-containing flame retardants do not dissolve in common NMR solvents (typically CDCI3 and tetrachloroethane), ll 1-NMR can not generally be applied and 13C s-NMR may then be called in. However, in favourable circumstances, e.g. for FR 1025 (poly-pentabromobenzylacrylate, Ameribrom) in PBT (Tribit 1500 GN 30), direct H 1-NMR in C2D2Cl4 of the fraction insoluble in HFIP can be used, in view of the unique resonance position of the benzylacrylate fragment in FR-1025. 

Watanabe, I., Tatsukawa, R. (1989) Anthropogenic brominated aromatics in the Japanese environment. In Proceedings Workshop on Brominated Aromatic Flame Retardants, pp. 63-70. Skokloster, Sweden, 24-26 October, 1989. 

T. Handa, T. Nagashima and N. Ebihara, Synergistic Action of Sb2(>3 with Bromine-Containing Flame Retardants in Polyolefins. II. Structure-Effect Relationships in Flame Retardant Systems," J. of Fire Retardant Chemistry,, 37 (1981). ... 

Experiments pertaining to a new system for the application of bromine to flame retardant polypropylene and foamed polystyrene are described. The FR compound, ammonium bromide, is formed in the amorphous regions of the polymer phase by the interaction of bromine sorbed on the polymer and ammonia, sorbed subsequently. Gaseous nitrogen which is also produced, expands and brings about the rearrangement of the chains to produce a porous structure. The ammonium bromide produced is finely divided and imparts FR properties to the polymer. 

Table VII. ( 0.1./%Br) of Various Bromine Compounds in Flame Retarding Polystyrene...

Three flame retardants were compared in this study, namely, a brominated polycarbonate oligomer (58% bromine), a brominated polystyrene (68% bromine), and a brominated triaryl phosphate ester (60% bromine plus 4% phosphorus). These are described in Table I. Figures 1 and 2 compare the thermal stability of the brominated phosphate with commercial bromine-containing flame retardants by thermogravimetric analysis (TGA) and by differential scanning calorimetry (DSC). The brominated phosphate melts at 110°C and shows a 1% weight loss at 300°C. Brominated polycarbonate and brominated polystyrene are polymeric and are not as volatile at elevated temperatures as the monomeric flame retardants. 

Brominated phosphate heated in a glass tube in air at 300°C for 30 minutes remains a water-white liquid. This was compared with commercial bromine-containing flame retardants which melt they all turn color. The excellent color stability of this brominated phosphate ester makes it suitable for the high temperature processing of engineering plastics. 

Bromide analysis, of water, 26 41 Bromide ions, in development solution, 79 205-206 Bromides, 4 319-330 thorium, 24 763 titanium, 25 54 tungsten, 25 379 uranium, 25 439 Bromimide, 4 299, 319 Brominated additive flame retardants, 77 461-468, 471-473t Brominated Anthanthrone Orange, pigment for plastics, 7 367t Brominated aromatic compounds, 7 7 459 Brominated bisphenol A-based epoxy resins, 70 366... 

BROMINE-BASED FLAME RETARDANTS FOUND IN ARCTIC ANIMALS... 

Ricoh is adopting the use of a bromine-based flame retardant for ABS used in casings for cameras and the like... 

The Bromine Industry in particular, points out that non-brominated chemical flame retardants may be very hazardous and that the phase-out of BFRs may not be safe. The non-brominated alternatives listed in the above case studies are likely to be safer if they exhibit less persistence and bioaccumulation in living systems, but some do possess significant toxicity. In the last few years, some agencies have therefore investigated the relative merits of alternatives to BFRs. 

Harju M, Heimstad ES, Herzke D, Sandanger T, Posner S, Wania F (2009) Emerging new brominated flame retardants in flame retarded products and the environment. Report 2462, Norwegian Pollution Control Authority, Oslo, Norway... 

Bromine is primarily used in flame-retardants (40%). It is also used in drilling fluids (24%), brominated agricultural chemicals (13%), and biocides/water treatment (7%). 

Wantanabe I, Tatsukawa R. 1990. Anthropogenic aromatics in the Japanese environment. Workshop on brominated aromatic flame retardants, Skokloster, Sweden. KEMI, National Council Inspectorate, Solna, Sweden, 1990, 63-71. 

In an analogous way as described above, in the case of ABS polymers that are equipped with bromine containing flame retardants, pyrolysis oils with low bromine content can be obtained (133). This issue is important for processing scrap plastics from waste of elec-... 

Incubation in soils showed that polybrominated biphenyls were resistant to degradation, but were apparently not taken up by plants or leached into groundwater [261]. Commercial formulations of brominated aromatic flame retardants had variable composition some contained highly brominated phenols, but no evidence of contamination with dibenzodioxins and dibenzofurans was found [198]. 

Korea Ministry of Environment (KMOE), 2005c. Worldwide regulation status of bromin-ated flame retardants and response strategy in Korea. KMOE report (in Korean). Seoul, Korea. 

Kajiwara, N., Ueno, D., Ramu, K., Kamikawa, S., Yamada, T., Chung, K.H., Tanabe, S., 2004. Geographical distribution and temporal trends of polybrominated diphenyl ethers (PBDEs) in cetacean from Asian waters. The third international workshop on bromin-ated flame retardants. June 6-9, 2004. Canada, pp. 187-190. 

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