Butyl rubbers brominated

BUR bromo-isobutene-isoprene rubber (brominated butyl rubber)... 

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. 

The low unsaturation requires powerful curing systems whilst the hydrocarbon nature of the polymer causes bonding problems. To overcome these problems chlorinated and brominated butyl rubbers (CIIR and BUR) have been introduced and have found use in the tyre industry. 

Standard butyl rubber, which is a copolymer of isobutylene with about 2% of isoprene vulcanises in the same manner as natural rubber but, as it only contains a small proportion of polyisoprene, the cross-link percentage is much reduced. It is therefore not possible to make ebonite from a butyl rubber. The same vulcanisation chemistry, with some modifications, applies to ethylene-propylene terpolymers and brominated butyl rubber. 

Brominated butyl rubber, 4 436 development of, 4 434 manufacture, 4 400, 442—444 Brominated carbonate oligomers,... 

Al-Bromosuccinimide (NBS), 13 116 brominated butyl rubber from, 4 434 bromination reagent, 4 344 Bromothymol blue, 4 362t Bromotrichloroethane, 6 269 Bromotrifluoromethane, 4 348, 348t Bromous acid, 4 333... 

If the above test is positive, the sample may be further subjected to a modified Weber color test for polyisoprenes. For this test, an acetone-extracted polymer (0.05 g) is dissolved or suspended in carbon tetrachloride, treated with a little solution of bromine in carbon tetrachloride and heated in a water bath to remove excess bromine. The residue is then warmed with a little phenol. In the presence of polyisoprenes, the solid or the solution turns violet or purple and gives a purple solution with chloroform. The test is also positive for natural rubber and butyl rubber. 

With the aid of suitable sensitizers, polymers such as brominated butyl rubber, valuable because of their flame retardancy, may act as backbone polymers for a variety of grafting reactions. 

It is obvious from obtained results (Table 5.1) that brominated butyl rubber can be synthesized by proposed method. Moreover in turbulent regime halogenation of other elastomers in particular ethylene and propylene copolymers was carried out. 

Brominated butyl rubber Brominated isobutylene/isoprene copolymer. See Isobutylene/isoprene copolymer, brominated Brominated neopentyl glycol diglycidyl ether CAS 31452-80-9... 

Butyl rubber, brominated. See Isobutylene/isoprene copolymer, brominated Butyl rubber, chlorinated. See Isobutylene/isoprene copolymer, chlorinated Butyl salicylate... 

Synonyms BIIR Brominated butyl rubber Brominated isobutylene/isoprene copolymer Bromobutyl rubber 1,3-Butadiene, 2-methyl-, polymer with 2-methyl-1-propene, brominated Butyl rubber, brominated Isobutylene, isoprene polymer, brominated Definition Elastomer vulcanized by sulfur systems vulcanizate offers low gas permeability, good weather/ozone resist., better chem./heat resist, than butyl rubber... 

The formirlations based on EPDM and brominated butyl rubber are plasticized with PIB to obtain water tight joints of rubber membranes. Peroxide curing causes some degradation of brominated butyl rabber which tackifies product... 

Bromo butyl rubber 2225 Brominated butyl bromine content 1.3%, polymer... 

Polyvinyl halide n. A term sometimes used (almost exclusively in patents) for polymers and co-polymers of vinyl chloride. Aside from polyvinyl fluoride, which is more similar structurally to polyethylene, and brominated butyl rubber, which has enjoyed some use in the automobile-tire industry, no polymers containing the other halogens (bromine, iodine, and astatine) exist in commerce. 

Most butyl rubber is used in the tire industry. Isobutylene-based rubbers are used in underhood hose for the polymer s low permeability and temperature resistance, and high damping, resihent butyl rubbers are used for noise and vibration attenuation applications such as automotive mounts for the engine and vehicle. Chloro- and brominated butyl rubber formulations are used in automotive hose applications where contact with fuel or air conditioning fluids occurs. 

Phenylmercuric borate is 0.08 % soluble in water. Mercury is in this compound covalently bound to the phenyl group. It is incompatible with many anions, including halides. However a 0.004 % solution is compatible with up to 0.7 % sodium chloride. The active concentration is 0.002 %, but a concentration up to 0.004 % may be used to compensate losses by adsorption on the membrane filter, etc. Eye drop bottles with chlorine and bromine butyl rubber droppers cannot be used with phenylmercuric salts, because a precipitate will be formed. An alternative is packaging the eye drops in a bottle with a polypropylene dropper (see Sect. 24.4.2). Phenylmercuric borate causes few hypersensitivity reactions, but with prolonged use, there might be a risk of mercury deposition in the lens. 

The quality of rubber stoppers is important in relation to the release of substances or particles into the liquid, the ease with which the rubber can be punctured and the flexibility around the puncture opening. The most often used material is bromine butyl rubber. For oily injections, closures made from an oil resistant elastomer (sDicmie rubber) must be used. The Ph. Eur. describes requirements for rubber closures [33]. Rubber closures for containers for aqueous parenteral preparations are classified in two classes type-I-closures and type-II-closures. Type-II-closures have additional mechanical characteristics, for example being suitable for multiple piercing. 

Halogenated butyl rubber greatly extended the usefulness of butyl rubber by providing much higher vulcanization rates and improving the compatibility with highly unsaturated elastomers, such as natural rubber and styrene-butadiene rubber (SBR). These properties permitted the production of tubeless tires with chlorinated or brominated butyl innerliners. The retention of air pressure (5) and low intercarcass pressure (6) extended tire durability. 

BUR Brominated isobutylene-isoprene rubber (butyl rubber, brominated)... 

Cationic grafting from PVC often occurs at structural irregularities on the backbone. A similar uncertainty regarding the nature and concentration of the active centres in the grafting reaction surrounds the use of chlorinated and brominated butyl rubber backbones, chlorinated polycyclopentadiene, and chlorinated st rene-butadiene copolymers." The graft reaction of st3o ene into chlorosulphonated polyethylene appears to occur at tertiary chlorine sites and not at the sulphonyl chlorides. ... 

Brominated butyl rubbers are of interest for truck tyre inner tubes because of their heat resistance, in giant type inner tubes because they may be blended with natural rubber to give a useful combination of properties, and for a variety of other uses. 

In commercial halogenated butyl rubbers the extent of halogenation is small. One typical chlorobutyl rubber contains 1-1-1-3 wt% chlorine and a typical bromobutyl rubber 1-8-2-4% bromine. Brominated butyl rubber generally cures at a faster rate than chlorinated butyl. 

As with the isobutene-isoprene-divinyl benzene terpolymers, brominated butyl rubber may be cross-linked with peroxides. Best... 

Metal oxides, such as zinc oxide, are important vulcanizing agents for halogenated butyl rubbers. Two mechanisms have been suggested for the reaction of brominated butyl with zinc oxide ... 

With chloro- and bromobutyl rubbers, regular butyl rubber is considered a raw material that is being halogenated with either chlorine or bromine from the following sources, see Figure 4.7. 

A brominated butyl rubber can be prepared in a manner similar to the chlorinated version. Bromobutyl is structurally similar to chlorobutyl but contains approximately 2.0 wt % bromine (in the case of the Exxon product) and provides an additional level of crosslinking activity. ... 

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