Bromine Containing Flame Retardants

DOVER CHEMICAL CORP. Bromine Containing Flame Retardants  

Gardner 1 Percent Bromine 30 Percent Chlorine 29 Viscosity, Polse/25C 22 S.G./50C. 1.42 

Chemical Description Bromo-Chlor. Paraffin Low cost, highly efficient flame retardant with good color and color stability. Used to flame retard flexible and rigid polyurethane foam, textiles, carpet backing, PVC and adhesives. 

Gardner 2 Percent Bromine 26 Percent Chlorine 32 Viscosity, Poise/25C 15 S.G./50C. 1.38 Percent Phosphorus 1.2 

Chemical Description Bromo-Chlor. Paraffin w/Phos. 

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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). 

Study of the Thermal Behaviour of Bromine Containing Flame Retardants during Incineration... 

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. 

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). ... 

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. 

Dumler R, Lenoir HTD, Hutzinger O. 1989a. OBDF and PBDD from the combustion of bromine containing flame retarded polymers A survey. Chemosphere 19(12) 2023-2031. 

Dumler R, Thoma H, Lenoir D, et al. 1989b. Thennal formation of polybrominated dibenzodioxins (PBDD) and dibenzofurans (PBDF) from bromine containing flame retardants. Chemosphere 19(l-6) 305-308. 

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-... 

Because of the ease of formation of these flammable pyrolysis products, polyesters have LOI values of 20-22 vol% (see Table 2.4), and hence, burn readily and because of the styrene content, give heavy soot formation. As these resins are cured at room temperature, bromine-containing flame retardants, which would decompose in melt-processed, thermoplastic polymers, may be effectively used. 

There is only perhaps one significant case where low concentrations of an antioxidant shows flame-retardant behavior, in the case of certain hindered amine stabilizers (HAS) that at the normally used concentrations (<1 wt%), offer low levels of flame retardancy in polypropylene and show synergy with bromine-containing flame retardants.78 80... 

In 1997, successful treatment tests were completed on electric and electronic waste with bromine-containing flame retardants. For this test, 50 tons of WEEE plastics were mixed with some 250 tons of DSD waste. 

DOVER CHEMICAIi CORP. Bromine Containing Flame Retardants (Continued) ... 

Earlier in this chapter, it was indicated that the presence of halide ions (e.g., Cl and Br ) is undesirable because they tend to promote the corrosion of parts of the IC. Low-flammability requirements for these encapsulants are realized through the use of brominated epoxy resins in combination with antimony oxide (Sb203). For some time the brominated epoxies have been suspected as a possible source of Br ions. Since it is difficult to achieve low flammability for these encapsulants without the bromine-containing species, efforts have been made to arrive at bromine-containing flame retardants of greater hydrolytic stability so that the flame retardant does not inadvertently diminish the corrosion protection these encapsulants are expected to provide. 

Handa, T., Nagashima, T. and Ebihara, N. Synergistic action of Sb203 with bromine-containing flame retardant in polyolefins. Fire and Materials, 6, No. 1, 1 (1982)... 

Tetrabromobisphenol A [79-94-7]. This compoimd, a soUd, mp 179-181°C is the largest of the bromine-containing flame retardants. Tetrabromobisphenol A is available from Albemarle as SAYTEX CP-2000, Dead Sea Bromine as FR-1524, and Great Lakes Chemical as BA-59P. 

The newer families of polymeric or oligomeric or reacted-in bromine, as well as very high molecular weight chlorine- or bromine-containing flame retardants are well designed to avoid migration and to be innocuous environmentally, since they have essentially no water solubility or vapor pressure. 

Other examples of how metal-containing compounds act through a gas phase mechanism can be mentioned. Martin and Price [116] used triphenylic derivatives of antimony, arsenic, bismuth and tributyl acetates in order to reduce the combustibility of epoxy polymers. It is known that triphenylstibine evaporates without noticeable decomposition at temperature close to 360°C. The effectiveness of its action is greater than that of the bromine flame retardant (with 46% Br). Thus when there are 7 Sb atoms per 10 000 atoms of C in the substrate (O.S nol.% of additive) the oxygen index of the material is higher than in the case c 13.7 mol.% bromine-containing flame retardant, i.e. 350 Br atoms per 10 000 C atoms in the substrate when the concentrations are equal (2. metal atoms per 1000 C atoms), the effectiveness of the compound decreases in the sequence Sb > As > Bi > Sn. Since arsenic compounds are very toxic, they are not of interest in this respect. 

Alnminnm hydroxide (also known as alumina trihydrate) Bromine-containing flame retardant Chlorinated paraffin wax Decabromodiphenyl oxide... 

Instead, these type of flame retardants exhibit some drawbacks compared with bromine-containing flame retardants, such as low flame retardant efficiency and low thermal stability. Improved intumescent flame retardant systems have been found by formulating with zeolites and organoboron siloxanes (9). 

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