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2,4-Dimethyl-6-tert-butylphenol
2,4-Dimethyl-6-''tert''-butylphenol is the organic compound with the formula Me2(''tert''-Bu)C6H2OH (Me = methyl, ''tert''-Bu = tertiary butyl). It is a colorless oil that is classified as an alkylated phenol. Preparation, reactions, uses It is used as an antioxidant, e.g. to prevent gumming in fuels, and as an ultraviolet stabilizer. It is used in jet fuels, gasolines, and avgas. It is prepared by alkylation of xylenol with isobutylene. This alkylation provides a means to separate 2,4-xylenol from 2,5-xylenol since 2,4-dimethyl-6-tert-butylphenol is insoluble in 10% NaOH but 2,5-dimethyl-6-tert-butylphenol is soluble. Subsequent to separation, the tert-butyl group can be removed in strong acid. Tradenames One of its trade names is Topanol A. It is found in antioxidant mixtures AO-30, AO-31, AO-32, IONOL K72, IONOL K78, IONOL K98, and others. See also * 2,6-Di-''tert''-butylphenol *Butylated hydroxytoluene * Propofol (Structural isomer) *List of gasoline additives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Gasoline Additives
Petrol additives increase petrol's octane rating or act as corrosion inhibitors or lubricants, thus allowing the use of higher compression ratios for greater efficiency and power. Types of additives include metal deactivators, corrosion inhibitors, oxygenates and antioxidants. Some additives are harmful and are regulated or banned in some countries. Additives *Oxygenates ** Alcohols: *** Methanol (MeOH) *** Ethanol (EtOH); see also common ethanol fuel mixtures *** Isopropyl alcohol (IPA) *** ''n''-butanol (BuOH) *** Gasoline grade ''t''-butanol (GTBA) ** Ethers: *** Methyl tert-butyl ether (MTBE), now outlawed in many states of the U.S. for road use because of water contamination. *** Tertiary amyl methyl ether (TAME) *** Tertiary hexyl methyl ether (THEME) *** Ethyl tertiary butyl ether (ETBE) *** Tertiary amyl ethyl ether (TAEE) *** Diisopropyl ether (DIPE) * Antioxidants, stabilizers ** Butylated hydroxytoluene (BHT) ** 2,4-Dimethyl-6-tert-butylphenol ** 2,6-Di-tert-butylph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,6-Di-tert-butylphenol
2,6-Di-''tert''-butylphenol is an organic compound with the structural formula 2,6-((CH3)3C)2C6H3OH. This colorless solid alkylated phenol and its derivatives are used industrially as UV stabilizers and antioxidants for hydrocarbon-based products ranging from petrochemicals to plastics. Illustrative of its usefulness, it prevents gumming in aviation fuels. Production 2,6-Di-''tert''-butylphenol is prepared industrially via the Friedel–Crafts alkylation of phenol with isobutene catalyzed by aluminium phenoxide: :C6H5OH + 2 CH2=C(CH3)2 → ((CH3)3C)2C6H3OH In this way, approximately 2.5M kg/y are produced. Applications Its dominant use is as an antioxidant. 2,6-di-''tert''-butylphenol is a precursor to more complex compounds used as antioxidants and light-protection agents for the stabilization for polymers. Of particular note is methyl-3-(3,5-di-''tert''-butyl-4-hydroxyphenyl)-propionate (CAS# 6386-38-5), which is formed by the Michael addition of methyl methacrylat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (Catofin or similar processes).. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkylphenols
Alkylphenols are a family of organic compounds obtained by the alkylation of phenols. The term is usually reserved for commercially important propylphenol, butylphenol, amylphenol, heptylphenol, octylphenol, nonylphenol, dodecylphenol and related "long chain alkylphenols" (LCAPs). Methylphenols and ethylphenols are also alkylphenols, but they are more commonly referred to by their specific names, cresols and xylenols. Production The long-chain alkylphenols are prepared by alkylation of phenol with alkenes: :C6H5OH + RR'C=CHR" → RR'CH−CHR"−C6H4OH In this way, about 500M kg/y are produced. Environmental controversy over nonylphenols Alkylphenols are xenoestrogens. Long chain Alkylphenols have the most potent estrogenic activity. The European Union has implemented sales and use restrictions on certain applications in which nonylphenols are used because of their alleged "toxicity, persistence, and the liability to bioaccumulate" but the United States EPA has taken a slo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antioxidants
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, to prevent oxidation, and to foods to prevent spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress. The only dietary antioxidants are vitamins A, C, and E, but the term ''antioxidant'' has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. History As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propofol
Propofol, marketed as Diprivan, among other names, is a short-acting medication that results in a decreased level of consciousness and a lack of memory for events. Its uses include the starting and maintenance of general anesthesia, sedation for mechanically ventilated adults, and procedural sedation. It is also used for status epilepticus if other medications have not worked. It is given by injection into a vein, and the maximum effect takes about two minutes to occur and typically lasts five to ten minutes. Propofol is also used for medical assistance in dying in Canada. The medication appears to be safe for use during pregnancy but has not been well studied for use in this case. It is not recommended for use during a cesarean section. It is not a pain medication, so opioids such as morphine may also be used; however, whether or not they are always needed is not clear. Propofol is believed to work at least partly via a receptor for GABA. Propofol was discovered in 1977 ... [...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. BHT has also been postulated as an antiviral drug, but as of December 2022 , use of BHT as a drug is not supported by the scientific literature and it has not been approved by any drug regulatory agency for use as an antiviral. Natural occurrence Phytoplankton, including the green algae ''Botryococcus braunii'', as well as three different cyanobacteria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avgas
Avgas (aviation gasoline, also known as aviation spirit in the UK) is an aviation fuel used in aircraft with spark-ignited internal combustion engines. ''Avgas'' is distinguished from conventional gasoline (petrol) used in motor vehicles, which is termed ''mogas'' (motor gasoline) in an aviation context. Unlike motor gasoline, which has been formulated since the 1970s to allow the use of platinum-content catalytic converters for pollution reduction, the most commonly used grades of avgas still contain tetraethyllead (TEL), a toxic substance used to prevent engine knocking (premature detonation). There are ongoing experiments aimed at eventually reducing or eliminating the use of TEL in aviation gasoline. Kerosene-based jet fuel is formulated to suit the requirements of turbine engines which have no octane requirement and operate over a much wider flight envelope than piston engines. Kerosene is also used by most diesel piston engines developed for aviation use, such as tho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bounded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For example, protonation of methanol gives an elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasoline
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. On average, U.S. refineries produce, from a barrel of crude oil, about 19 to 20 gallons of gasoline; 11 to 13 gallons of distillate fuel (most of which is sold as diesel fuel); and 3 to 4 gallons of jet fuel. The product ratio depends on the processing in an oil refinery and the crude oil assay. A barrel of oil is defined as holding 42 US gallons, which is about 159 liters or 35 imperial gallons. The characteristic of a particular gasoline blend to resist igniting too early (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating, which is produced in several grades. Tetraethyl lead and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet Fuel
Jet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance. Jet fuel is a mixture of a variety of hydrocarbons. Because the exact composition of jet fuel varies widely based on petroleum source, it is impossible to define jet fuel as a ratio of specific hydrocarbons. Jet fuel is therefore defined as a performance specification rather than a chemical compound. Furthermore, the range of molecular mass between hydrocarbons (or different carbon numbers) is defined by the requirements for the product, such as the freezing point or smoke point. Kerosene-type jet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
