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Isobutylene
Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula . 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. Production Polymer and chemical grade isobutylene is typically obtained by dehydrating tertiary butyl alcohol (TBA) or catalytic dehydrogenation of isobutane.. Gasoline additives methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE), respectively, are produced by reacting methanol or ethanol with isobutylene contained in butene streams from olefin steam crackers or refineries, or with isobutylene from dehydrated TBA. Isobutylene is not isolated from the olefin or refinery butene stream before the reaction, as separating the ethers from the remaining butenes is simpler. Isobutylene can also be produced in high purities by "back-cracking" MTBE or ETBE at high temperatures and then separating the isobutylene by distillation from methan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butene
Butene, also known as butylene, is an alkene with the formula . The word ''butene'' may refer to any of the individual compounds. They are colourless gases that are present in crude oil as a minor constituent in quantities that are too small for viable extraction. Butene is therefore obtained by catalytic cracking of long-chain hydrocarbons left during refining of crude oil. Cracking produces a mixture of products, and the butene is extracted from this by fractional distillation. Butene can be used as the monomer for polybutene, but this polymer is more expensive than alternatives with shorter carbon chains such as polypropylene. Polybutene is therefore used in more specialized applications. Butenes are more commonly used to make copolymer (mixed with another monomer such as ethylene). Butenes are major constituents of raffinates, the C4 fractions in oil processing. The raffinates containing butadiene are considered carcinogenic and mutagenic. They can be used as feedstocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of UN Numbers 1001 To 1100
UN numbers from UN1001 to UN1100 as assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods are as follows: __NOTOC__ UN 1001 to UN 1100 n.o.s. = ''not otherwise specified'' meaning a collective entry to which substances, mixtures, solutions or articles may be assigned if a) they are not mentioned by name in ''3.2 Dangerous Goods List'' AND b) they exhibit chemical, physical and/or dangerous properties corresponding to the Class, classification code, packing group and the name and description of the n.o.s. entry See also * Lists of UN numbers References External linksADR Dangerous Goods cited on 2 June 2015.UN Dangerous Goods List from 2015 cited on 2 June 2015.UN Dangerous Goods List from 2013 cited on 2 June 2015. {{UN number list navbox Lists of UN numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Tert-butyl Ether
Methyl ''tert''-butyl ether (MTBE), also known as ''tert''-butyl methyl ether, is an organic compound with a structural formula (CH3)3COCH3. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. Primarily used as a fuel additive, MTBE is blended into gasoline to increase its octane rating and knock resistance, and reduce unwanted emissions. Production and properties MTBE is manufactured via the chemical reaction of methanol and isobutylene. Methanol is primarily derived from natural gas, where steam reforming converts the various light hydrocarbons in natural gas (primarily methane) into carbon monoxide and hydrogen. The resulting gases then further react in the presence of a catalyst to form methanol. Isobutylene can be produced through a variety of methods. ''n''-butane can be isomerized into isobutane which can be dehydrogenated to isobutylene. In the Halcon process, ''t''-Butyl hydroperoxide derived from isobutane oxygenation is tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyl Rubber
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, (C4H8)n, is the homopolymer of isobutylene, or 2-methyl-1-propene, on which butyl rubber is based. Butyl rubber is produced by polymerization of about 98% of isobutylene with about 2% of isoprene. Structurally, polyisobutylene resembles polypropylene, but has two methyl groups substituted on every other carbon atom, rather than one. Polyisobutylene is a colorless to light yellow viscoelastic material. It is generally odorless and tasteless, though it may exhibit a slight characteristic odor. Properties Butyl rubber has excellent impermeability to gas diffusion, and the long polyisobutylene segments of its polymer chains give it good flex properties. The formula for PIB is: –(–CH2–C(CH3)2–)n– The formula for IIR is: It can be made from the monomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquefied Petroleum Gas
Liquefied petroleum gas, also referred to as liquid petroleum gas (LPG or LP gas), is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, Butane, ''n''-butane and isobutane. It can also contain some propylene, butylene, and isobutylene/Isobutylene, isobutene. LPG is used as a fuel gas in HVAC, heating appliances, cooking equipment, and vehicles, and is used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce the damage it causes to the ozone layer. When specifically used as a vehicle fuel, it is often referred to as autogas or just as Autogas#Terminology variations and confusion, gas. Varieties of LPG that are bought and sold include mixes that are mostly propane (), mostly butane (), and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane. In the United States, mainly two grad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butylated Hydroxyanisole
Butylated hydroxyanisole (BHA) is a synthetic, waxy, solid petrochemical. Its antioxidant properties have caused it to be widely used as a preservative in food, food packaging, animal feed, cosmetics, pharmaceuticals, rubber, and petroleum products. BHA has been used in food since around 1947. Chemistry BHA consists of a mixture of two isomeric organic compounds, 2-''tert''-butyl-4-hydroxyanisole and 3-''tert''-butyl-4-hydroxyanisole. It is prepared from 4-methoxyphenol and isobutylene. The conjugated aromatic ring of BHA is able to stabilize free radicals, sequestering them. By acting as free radical scavengers, further free radical reactions are prevented. Applications Since 1947, BHA has been added to edible fats and fat-containing foods for its antioxidant properties as it prevents rancidification of food which creates objectionable odors. It has been assigned the E number E320. It is often combined with a similar chemical, butylated hydroxytoluene (BHT). BHA also is common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butylated Hydroxytoluene
Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. BHT is widely used to prevent free radical-mediated oxidation in fluids (e.g. fuels, oils) and other materials, and the regulations overseen by the U.S. F.D.A.—which considers BHT to be "generally recognized as safe"—allow small amounts to be added to foods. Despite this, and the earlier determination by the National Cancer Institute that BHT was noncarcinogenic in an animal model, societal concerns over its broad use have been expressed. Natural occurrence Phytoplankton, including the green algae '' Botryococcus braunii'', as well as three different cyanobacteria ('' Cylindrospermopsis raciborskii'', '' Microcystis aeruginosa'' and '' Oscillatoria'' sp.) are capable of producing BHT as a natural product. The fruit lychee also produces BHT in its pericarp. Several fungi (for example '' As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethenolysis
In organic chemistry, ethenolysis is a chemical process in which internal olefins are degraded using ethylene () as the reagent. The reaction is an example of olefin metathesis, cross metathesis. The utility of the reaction is driven by the low cost of ethylene as a reagent and its selectivity. It produces compounds with terminal alkene functional groups (α-olefins), which are more amenable to other reactions such as polymerization and hydroformylation. The general reaction equation is: :\ce + \longrightarrow \ce + \ce Ethenolysis is a form of methylenation, i.e., the installation of Methylene group, methylene () groups. Applications Terminal alkenes Using ethenolysis, higher molecular weight internal alkenes can be converted to more valuable terminal alkenes. The Shell higher olefin process (SHOP process) uses ethenolysis on an industrial scale. SHOP α-olefin mixtures are first separated by distillation. Higher molecular weight fractions are Isomerization, isomerized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerization
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them. In chemical compounds, polymerization can occur via a variety of reaction mechanisms that vary in complexity due to the functional groups present in the reactants and their inherent steric effects. In more straightforward polymerizations, alkenes form polymers through relatively simple radical reactions; in contrast, reactions involving substitution at a carbonyl group require more complex synthesis due to the way in which reactants polymerize. As alkenes can polymerize in somewhat straightforward radical reactions, they form useful compounds such as polyethylene and polyvinyl chloride (PVC), which are produced in high tonnages each year due to their usefulnes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol
Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. It is acutely toxic and is considered a health hazard. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 million tonnes a year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds, and is a liquid when manufactured. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, explosives such as picric acid, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceuti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
