Ethane flame properties

The traditional halogen fire retardants used in styrenic copolymers are decabromodiphenyl ether and octabromodiphenyl ether, tetrabromobisphenol A, bis(tribromophenoxy) ethane, ethylene bis-tetrabromophthalimide, and chlorinated paraffins. Actually the octabromodiphenyl ether has been banned on precautionary principles, as will be explained below. The fire-retardant capabilities of the more effective halogen-containing compounds are in line with the quantity of halogen in the final polymer blend, with consideration for the use of synergists. Thus, the practical utility of these flame-retardant compounds (once the issue of degradation temperature is resolved) is often based on their ability to be blended into the polymer and to not substantially affect the physical properties of the polymers. 

Tetrabromobisphenol A is used in epoxy resins especially for glass fiber reinforced used in printed circuit board. Nonreactive compounds such as tetrabromophatalate ester, bis(tribromophenoxy) ethane, and decabromodiphenyl ether are also used. The use of synergists, such as antimony oxide, reduces the quantity of brominated flame retardant necessary but decreases the electrical properties required. 

The effect of additives, others than plasticizers, on the dynamic mechanical properties of styrene polymers have attracted little attention from researchers. Flame retardants such as l,2-bis(tetrabromophthalimide)ethane, crystalline decabromodiphenyl oxide (DBDPO) and antimony trioxide (Sb203) do not affect the a relaxation of aPS [38,39]. 

In a study of 78 TV sets and 34 personal computers, 78% of the modified polystyrene housings contained PBDEs, 16% PBBs, and 3% l,2-bis-(tribromo-phenoxy)ethane. Composed samples of this material with PBDEs and PBBs as flame retardants already contained traces of PBDFs and PBDDs. When PBBs were used as flame retardant, the levels of these impurities increased during the recycling process. The formation of these PBDFs and PBDDs from the primary flame retardants, should also be considered when assessing the toxic properties of PBBs and PBDEs [25]. 

As a result of both gradual voluntary production cuts and legislative measures, production of technical mixtures of PBDEs has decreased and conversely there have been increases in the production of alternative non-PBDE flame retardants. The alternative retardants include bis(2,4,6-tribromophenoxy)ethane (BTBPE, 12-141), octabromo-1-phenyl-1,3,3-trimethyhndane (Br indane, 12-142), decabromodiphenylethane (DBDPE, 12-143) and certain other compounds. These substances have similar properties to PBDEs, contain an aromatic nucleus, more bromine atoms and are... 

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