Halogenation 1742 INDEX

Di- and poly-halogenated aliphatic hydrocarbons. No general procedure can be given for the preparation of derivatives of these compounds. Reliance must be placed upon their physical properties (b.p., density and refractive index) and upon any chemical reactions which they undergo. 

DMPPO—polystyrene blends, because of the inherent flame resistance of the DMPPO component (oxygen index ca 29.5), can be made flame retardant without the use of halogenated additives that tend to lower impact strength and melt stabiUty in other polymers. Approximately one-half of total Noryl sales volume is in flame-retarded grades, ie, VO or VI in a 1.6-mm section (UL-94). 

Ba(B02)2 H2O, used in flame retardant plastic formulations as a synergist for phosphoms or halogen compounds and as a partial or complete replacement for antimony oxide (see Flame RETARDANTS), is excellent as an afterglow suppressant. The low refractive index of results in greater... 

Properties and Applieations. Aryloxyphosphazene elastomers using phenoxy and J-ethylphenoxy substituents have found interest in a number of appHcations involving fire safety. This elastomer has a limiting oxygen index of 28 and contains essentially no halogens. It may be cured using either peroxide or sulfur. Peroxide cures do not require the allyhc cute monomer. Gum physical properties are as follows (17) ... 

There is an anomaly in the higher index value for dichloromethane compared with chloroform although dichloromethane is noted for being the less toxicity halogenous solvent. But this figure only reflects the extreme volatility of this substance since its LC50 is lower than the one for chloroform. There is probably a similar problem for acetonitrile, which is underestimated by this approach. 

AS A FLAME RETARDANT. The zinc borate is an efficient synergist of organic halogen sources. In certain halogen-containing systems such as unsaturated polyester, epoxy (3), and rigid PVC, the zinc borate alone can outperform antimony oxide as shown by the Oxygen Index and UL-94 tests (Fig. 3, 4, and 5). 

In other halogen-containing systems, such as flexible PVC and polyolefins, it is preferable to use the zinc borate in conjunction with antimony oxide for maximum performance. In flexible PVC, for example, the zinc borate alone is not very effective in the Oxygen Index test (Fig. 6), but a combination of the zinc borate and antimony oxide (1 1 ratio) outperforms equal weight of antimony oxide at a total loading of more than 10 phr (4). In the presence of alumina trihydrate (ATH), the beneficial effect of using a combination of the zinc borate and antimony oxide is dramatically increased (Fig. 7). 

As with other non-metal derivatives, reactivity depends on chain-length, branching and degree of halogen substitution. Individually indexed compounds are ... 

As with other non-metal derivatives, reactivity depends on chain-length, branching and degree of halogen substitution. Individually indexed compounds are f Chloromethylphenylsilane, 2810 f Chlorotrimethylsilane, 1304 f Cyanotrimethylsilane, 1665 f Dichlorodiethylsilane, 1683 f Dichlorodimethylsilane, 0902 f Dichloroethylsilane, 0903 f Dichloromethylsilane, 0470 f Dichloromethylvinylsilane, 1208 f Iodotrimethylsilane, 1306 f Methyltrichlorosilane, 0439 f Trichloroethylsilane, 0854 f Trichlorovinylsilane, 0746... 

CYANO COMPOUNDS, DIENES, HALOACETYLENE DERIVATIVES, HALOGEN OXIDES, METAL ACETYLIDES, METAL FULMINATES, OXIDES OF NITROGEN The individually indexed endothermic compounds, for most of which heats of formation are given in the text f Acetonitrile, 0758... 

The name adopted for this group of highly reactive (and in some circumstances intramolecularly self-reactive) compounds is intended to cover both arylmetal halides (halogen bonded to the metal) and haloaryl metals (halogen attached to the aryl nucleus). Individually indexed compounds are ... 

The degree of reactivity to air or to water depends on the degree of substitution of hydrogen by halogen. This highly reactive group includes the individually indexed compounds ... 

For specific polymers, halogen-free and phosphorus-free plasticizers can reduce the oxygen index. The transparency can be altered if the compatibility is low and/or the refractive index is inadequate. 

Matsushita website (2003). Examples of products which do not contain halogens. See http //www.matsushita. co.jp/environment/2000e/gproducts/ index3 1. html See also their lead-free information available at http //www. semicon. Panasonic.co.jp/lead-free/e-index.html... 

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