Additives brominated hydrocarbons

Commercial chemical fibers are combustible in nature, and improved FR properties must be considered in actual application. Most FR additives contain bromine (Br), chlorine (Cl), phosphorus (P), antimony, or aluminum. Among them, commonly used additives are additive brominated hydrocarbons and reactive brominated hydrocarbons, nonhalogenated phosphate esters, halogenated phosphate esters, trioxide antimony oxide, pentoxide antimony oxide and sodium derivatives, chlorinated hydrocarbons like chlorinated paraffin, and chlorinated cycloaUphatics. Others include chlorinated or brominated compounds, fluorinated compounds, magnesium carbonate, magnesium hydroxide, melamine, molybdenum compounds, silicone polymer, and zinc borate. Sometimes, polymers are chemically modified, and N, P, Cl, fluorine (F), silicon (Si), and Br elements can be introduced into the polymer main chain [49]. 

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... 

Most FR additives contain bromine, chlorine, phosphorus, antimony, or aluminium. Among the main types are brominated hydrocarbons additive and reactive phosphate esters non-halogenated and halogenated antimony oxide trioxide and pentoxide, and sodium derivatives chlorinated hydrocarbons chlorinated paraffins, chlorinated cycloaliphatics. Other types include chlorinated/ brominated compounds, fluorinated compounds, magnesium carbonate, magnesium hydroxide, melamine, molybdenum compounds, silicone polymer. 

Brominated Hydrocarbons. Accounting for the highest dollar value, these consist of additives such as decabromodiphenyloxide [1163-19-5] and tetra-bromobishphenol A [79-94-7] and derivatives. These products are used in engineering resins primarily (HIPS, ABS, and PC) for the business machine market. Typically they are used with antimony oxide [1309-64-4] as a synergist in a ratio of 3 1 respectively. Major suppliers of brominated FRs are Great Lakes Chemical Co. (GLCC), Albemarle (Saytex), and Dead Sea Bromine. 

This method follows the ASTM D 1159 and D 2710 procedures and the AFNOR M 07-017 standard. It exploits the capacity of the double olefinic bond to attach two bromine atoms by the addition reaction. Expressed as grams of fixed bromine per hundred grams of sample, the bromine number, BrN, enables the calculation of olefinic hydrocarbons to be made if the average molecular weight of a sufficiently narrow cut is known. 

Many of the reactions of halogens can be considered as either oxidation or displacement reactions the redox potentials (Table 11.2) give a clear indication of their relative oxidising power in aqueous solution. Fluorine, chlorine and bromine have the ability to displace hydrogen from hydrocarbons, but in addition each halogen is able to displace other elements which are less electronegative than itself. Thus fluorine can displace all the other halogens from both ionic and covalent compounds, for example... 

A solution prepared by dissolving 2 g. of biomine in 100 g. of carbon tetra. chloride is satisfactory. Carbon tetrachloride is employed because it is an excellent solvent for bromine as well as for hydrocarbons it possesses the additional advan. tage of low solubility for hydrogen bromide, the evolution of which renders possible the distinction between decolourisation of bromine due to substitution or due to addition. 

The classification of hydrocarbons as aliphatic or aromatic took place m the 1860s when It was already apparent that there was something special about benzene toluene and their derivatives Their molecular formulas (benzene is CgHg toluene is C7Hj ) indicate that like alkenes and alkynes they are unsaturated and should undergo addition reac tions Under conditions m which bromine for example reacts rapidly with alkenes and alkynes however benzene proved to be inert Benzene does react with Bi2 m the pres ence of iron(III) bromide as a catalyst but even then addition isn t observed Substitu tion occurs instead ... 

Other nonpolymeric radical-initiated processes include oxidation, autoxidation of hydrocarbons, chlorination, bromination, and other additions to double bonds. The same types of initiators are generally used for initiating polymerization and nonpolymerization reactions. Radical reactions are extensively discussed in the chemical Hterature (3—15). 

Halogenated Butyl Rubber. The halogenation is carried out in hydrocarbon solution using elemental chlorine or bromine in a 1 1 molar ratio with enchained isoprene. The reactions ate fast chlorination is faster. Both chlorinated and brominated butyl mbbers can be produced in the same plant in blocked operation. However, there are some differences in equipment and reaction conditions. A longer reaction time is requited for hromination. Separate faciUties are needed to store and meter individual halogens to the reactor. Additional faciUties are requited because of the complexity of stabilising brominated butyl mbber. 

As with addition of other electrophiles, halogenation of conjugated dienes can give 1,2- or 1,4-addition products. When molecular bromine is used as the brominating agent in chlorinated hydrocarbon solvent, the 1,4-addition product dominates by 7 1 in the case of butadiene. ... 

Although, in most cases, iodine is a fairly inert halogen (in contrast to bromine) and does not normally react with the substances that have been chromatographed there are, nevertheless, examples where chemical changes have been observed. Oxidations can evidently take place (e.g. aromatic hydrocarbons and isoquinoline alkaloids [252,253]) and additions and substitutions have also been observed. Pale zones then appear on a brown background. 

Additions of halogen fluorides to the more electrophilic perfluonnated olefins generally require different conditions Reactions of iodine fluoride, generated in situ from iodine and iodine pentafluoride [62 102 103, /05] or iodine, hydrogen fluoride, and parapeiiodic aud [104], with fluormated olefins (equations 8-10) are especially well studied because the perfluoroalkyl iodide products are useful precursors of surfactants and other fluorochemicals Somewhat higher temperatures are required compared with reactions with hydrocarbon olefins Additions of bromine fluoride, from bromine and bromine trifluonde, to perfluonnated olefins are also known [lOti]... 

The influence of the OH-group on the reactivity of the benzene ring is of great importance. All substitution processes which are traced back to preliminary addition reactions take place much more easily with the phenols than with the hydrocarbons as far as possible the groups which enter occupy the o- and p-positions. A number of reactions illustrating this statement is discussed below and in subsequent parts of this book. It may be mentioned here that by the action of bromine water, o-o-p-tnbromophenol is at once precipitated from an aqueous solution of phenol. (Method for the quantitative determination of phenol.)... 

Kekule, a German chemist, was the first to propose a structure for benzene In 1865. It was a cyclic structure of alternating single and double bonds. The Kekule structure, however, does not fit all the evidence that chemists have since collected. For example, when benzene Is added to a bromine solution, rapid decolourlsatlon does not take place. This Implies that benzene resists addition reactions and Is much more stable than a typical unsaturated hydrocarbon. The reason for this becomes clear when we examine more closely the structure and bonding In benzene. 

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