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1,3-Butadiene hydrohalogenation

Tranv-1,4- and 1,2-polybutadiene can be hydrohalogenated under mild conditions with gaseous HCl. The same is true of copolymers of butadiene with piperylene and also of isotactic transAA-piperylene. The addition of HCl to the asymmetric double bond is trans for polypiperylene and occurs in a stereoselective way, judging from the NMR spectra. [Pg.407]

Halogenation and hydrohalogenation of elastomers have been reported extensively in the literature [26]. The main problems with these reactions are the cyclization and chain scission that occur parallel to the halogenation reaction. These introduce difficult problems in the characterization of the resulting products. Despite these problems, several products have been prepared and commercialized. Chlorination of poly(l, 4-butadiene) to prepare a product similar to poly(vinyl chloride) has been reported by several workers [27]. This process had extensive side reactions and chain degradation. The chlorination of butyl rubber and conjugated diene-butyl rubbers gives end products that are used in the tire industry as inner liners for air retention. [Pg.507]

FIGURE 12.35 Hydrohalogenation of 1,3-butadiene with HCI produces the products resulting from a 1,2- and a 1,4-addition (red numbers not lUPAC). [Pg.534]

Since 1,4-polyisoprene has a secondary carbon atom at the double bond it follows that it is generally more reactive to both free radicals and to carbonium ions than 1,4-poly butadiene. The typical addition reactions associated with the double bond suggest that the ultimate hydrogenated, halogenated, hydrohalogenated and isomerized diene polymers would have the same structure irrespective of the initial cis-ltrans- ratio. [Pg.165]

Representative diene-based polymers include natural rubber (NR), polyisoprene (PIP), PBD, styrene—butadiene rubber (SBR), and acrylonitrile-butadiene rubber (NBR), which together compose a key class of polymers widely used in the rubber industry. These unsaturated polyolefins are ideal polymers for chemical modifications owing to the availability of parent materials with a diverse range of molecular weights and suitable catalytic transformations of the double bonds in the polymer chain. The chemical modifications of diene-based polymers can be catalytic or noncatalytic. The C=C bonds of diene-based polymers can be transformed to saturated C—C and C—H bonds (hydrogenation), carbonyls (hydrofbrmylation and hydrocarboxylation), epoxides (epoxidation), C—Si bonds (hydrosilylation), C—Ar bonds (hydroarylation), C—B bonds (hydroboration), and C—halogen bonds (hydrohalogenation). ... [Pg.3]


See other pages where 1,3-Butadiene hydrohalogenation is mentioned: [Pg.215]    [Pg.215]    [Pg.40]    [Pg.78]    [Pg.289]    [Pg.280]    [Pg.526]    [Pg.534]   
See also in sourсe #XX -- [ Pg.1144 ]




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Hydrohalogenation

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