Chemical reaction halogenation

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. 

Fiber-Reactive Dyes. These dyes can enter iato chemical reaction with the fiber and form a covalent bond to become an iategral part of the fiber polymer. They therefore have exceptional wetfastness. Thein main use is on ceUulosic fibers where they are appHed neutral and then chemical reaction is initiated by the addition of alkaH. Reaction with the ceUulose can be by either nucleophilic substitution, using, for example, dyes containing activated halogen substituents, or by addition to the double bond in, for example, vinyl sulfone, —S02CH=CH2, groups. 

Polyolefins such as polyethylene and polypropylene contain only C—C and C—H bonds and may be considered as high molecular weight paraffins. Like the simpler paraffins they are somewhat inert and their major chemical reaction is substitution, e.g. halogenation. In addition the branched polyethylenes and the higher polyolefins contain tertiary carbon atoms which are reactive sites for oxidation. Because of this it is necessary to add antioxidants to stabilise the polymers against oxidation Some polyolefins may be cross-linked by peroxides. 

The control of chemical reactions (e.g., esterification, sulfonation, nitration, alkylation, polymerization, oxidation, reduction, halogenation) and associated hazards are an essential aspect of chemical manufacture in the CPI. The industries manufacture nearly all their products, such as inorganic, organic, agricultural, polymers, and pharmaceuticals, through the control of reactive chemicals. The reactions that occur are generally without incident. Barton and Nolan [1] examined exothermic runaway incidents and found that the principal causes were ... 

The chemical reactions of XY can be conveniently classified as (a) halogenation reactions, (b) donor-acceptor interactions and (c) use as solvent systems. Reactions frequently parallel those of the parent halogens but with subtle and revealing differences. CIF is an effective fluorinating agent (p. 820) and will react with many metals and non-metals either at room temperature or above, converting them to fluorides and liberating chlorine, e.g. ... 

The most characteristic chemical reaction of an alkene is an addition reaction, in which atoms supplied by the reactant form o-bonds to the two atoms originally joined by the double bond (Fig. 18.9). In the process, the 7r-bond is lost. An example is halogenation, the addition of two halogen atoms at a double bond, as in the formation of 1,2-dichloroethane ... 

Fig. 6. Chemical reactions used for CPO formation reactions R, P porphyrin moieties, X halogen, A counter anion, and I ligand)...

In contrast to chemical reactions in which elimination and nucleophilic displacement are alternatives and may occur simultaneously, microbial elimiuation is less common. This term is also used for the reactiou iu which, for example, 1,2-dihaloethaues are transformed to ethene, in contrast to dehydro-halogenation in which a haloethene is produced or reductive hydrogenolysis to a haloethaue. Degradatiou iuvolviug elimiuation is found in several degradations ... 

Numerous chemical reactions have been carried out on ferrocene and its derivatives.317 The molecule behaves as an electron-rich aromatic system, and electrophilic substitution reactions occur readily. Reagents that are relatively strong oxidizing agents, such as the halogens, effect oxidation at iron and destroy the compound. 

Saturated and unsaturated fatty acids have different chemical properties. Halogens can be easily added to fats that contain carbon-carbon double bonds. The reaction may be shown as l2 + R-CH = CH-R — R-CHI-CHI-R. ... 

Afterburners may be of the flame, thermal, or catalytic type. In each case the object is to cause a chemical reaction which will result in an acceptable product, such as water and carbon dioxide. This is not possible, hence this is an undesirable method, if heavy metals, sulfides, halogens, or phosphates are present. The costs associated with this method are given in reference 22. 

Chemical reactions are used to modify existing polymers, often for specialty applications. Although of considerable importance for plastics, very few polymer reactions (aside from crosslinking) are important for elastomers. Chlorination and bromination of Butyl rubber to the extent of about one halogen atom per isoprene unit yields elastomers which are more easily crosslinked than Butyl rubber. Substitution occurs with rearrangement to yield an allylic halide structure... 

The most commonly used and widely marketed GC detector based on chemiluminescence is the FPD [82], This detector differs from other gas-phase chemiluminescence techniques described below in that it detects chemiluminescence occurring in a flame, rather than cold chemiluminescence. The high temperatures of the flame promote chemical reactions that form key reaction intermediates and may provide additional thermal excitation of the emitting species. Flame emissions may be used to selectively detect compounds containing sulfur, nitrogen, phosphorus, boron, antimony, and arsenic, and even halogens under special reaction conditions [83, 84], but commercial detectors normally are configured only for sulfur and phosphorus detection [85-87], In the FPD, the GC column extends... 

---