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Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula (CH 3) 2 C=CH 2. It is a four-carbon branched alkene (olefin), one of the four isomers of butylene . It is a colorless flammable gas, and is of considerable industrial value.
Butyl rubber, sometimes just called "butyl", is a synthetic rubber, a copolymer of isobutylene with isoprene. The abbreviation IIR stands for isobutylene isoprene rubber. Polyisobutylene, also known as "PIB" or polyisobutene, (C 4 H 8) n, is the homopolymer of isobutylene, or 2-methyl-1-propene, on which butyl rubber is based. Butyl rubber is ...
The reaction conditions for the synthesis of each type of isobutylene product vary depending on the desired molecular weight and what type(s) of monomer(s) is used. The conditions most commonly used to form low molecular weight (5–10 x 10 4 Da) polyisobutylene are initiation with AlCl 3, BF 3, or TiCl 4 at a temperature range of −40 to 10 ...
The tert-butyl substituent is very bulky and is used in chemistry for kinetic stabilization, as are other bulky groups such as the related trimethylsilyl group. The effect of the tert-butyl group on the progress of a chemical reaction is called the Thorpe–Ingold effect illustrated in the Diels-Alder reaction below.
This colorless gas is structurally similar to isobutylene. It is used as a comonomer in the production of modified polyvinylidene fluoride. It is produced in a multistep process starting with the reaction of acetic anhydride with hexafluoroacetone. [1] It is oxidized by sodium hypochlorite to hexafluoroisobutylene oxide.
Isobutylene can be produced through a variety of methods. n-butane can be isomerized into isobutane which can be dehydrogenated to isobutylene. [7] In the Halcon process, t-Butyl hydroperoxide derived from isobutane oxygenation is treated with propylene to produce propylene oxide and t-butanol. The t-butanol can be dehydrated to isobutylene.
Living cationic polymerization is a living polymerization technique involving cationic propagating species. [1] [2] It enables the synthesis of very well defined polymers (low molar mass distribution) and of polymers with unusual architecture such as star polymers and block copolymers and living cationic polymerization is therefore as such of commercial and academic interest.
AMPS is made by the Ritter reaction of acrylonitrile and isobutylene in the presence of sulfuric acid and water. [2] The recent patent literature [3] describes batch and continuous processes that produce AMPS in high purity (to 99.7%) and improved yield (up to 89%, based on isobutene) with the addition of liquid isobutene to an acrylonitrile / sulfuric acid / phosphoric acid mixture at 40°C.