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Model Cement
Butanone, also known as methyl ethyl ketone (MEK), is an organic compound with the chemical formula, formula CH3C(O)CH2CH3. This colourless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in nature only in trace amounts.Wilhelm Neier, Guenter Strehlke "2-Butanone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. It is partially soluble in water, and is commonly used as an industrial solvent. It is an isomer of another solvent, tetrahydrofuran. Production Butanone may be produced by oxidation of 2-butanol. The dehydrogenation of 2-butanol is catalyst, catalysed by copper, zinc, or bronze: :CH3CH(OH)CH2CH3 → CH3C(O)CH2CH3 + H2 This is used to produce approximately 700 million kilograms yearly. Other syntheses that have been examined but not implemented include Wacker oxidation of 2-butene and oxidation of isobutylbenzene, which is analogous to the industrial production of acet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merck Index
''The Merck Index'' is an encyclopedia of chemical substance, chemicals, pharmaceutical drug, drugs and biomolecule, biologicals with over 10,000 monographs, monograph on single substances or groups of related chemical compound, compounds published online by the Royal Society of Chemistry. History The first edition of the Merck's Index was published in 1889 by the German chemical company Merck Group, Emanuel Merck and was primarily used as a sales catalog for Merck's growing list of chemicals it sold. The American subsidiary was established two years later and continued to publish it. During World War I the US government seized Merck's US operations and made it a separate American "Merck" company that continued to publish the Merck Index. In 2012 the Merck Index was licensed to the Royal Society of Chemistry. An online version of The Merck Index, including historic records and new updates not in the print edition, is commonly available through research libraries. It also include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In precise chemical terms, nitrocellulose is not a nitro compound, but a nitrate ester. The glucose repeat unit (anhydroglucose) within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Acetate
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In cellulose acetate film, photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce. History In 1865, French chemist Paul Schützenberger discovered that cellulose reacts with acetic anhydride to form cellulose acetate. The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903. In 1904, Camille Dreyfus (chemist), Camille Dreyfus and his younger brother Henri Dreyfus, Henri performed chemical research and development on cellulose acetate in a shed in their father's garden in Basel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on naturally occurring resins. Plants secrete resins for their protective benefits in response to injury. The resin protects the plant from insects and pathogens. Resins confound a wide range of herbivores, insects, and pathogens, while the volatile phenolic compounds may attract benefactors such as parasitoids or predators of the herbivores that attack the plant. Composition Most plant resins are composed of terpenes. Specific components are alpha-pinene, beta-pinene, delta-3 carene, and sabinene, the monocyclic terpenes limonene and terpinolene, and smaller amounts of the tricyclic sesquiterpenes, longifolene, caryophyllene, and delta-cadinene. Some resins also contain a high proportion of resin acids. Rosins on the other hand are less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gum
Natural gums are polysaccharides of natural origin, capable of causing a large increase in a solution's viscosity, even at small concentrations. They are mostly botanical gums, found in the woody elements of plants or in seed coatings. Human uses They are used in the food industry as thickening agents, gelling agents, emulsifying agents, and stabilizers, and in other industrial adhesives, binding agents, crystal inhibitors, clarifying agents, encapsulating agents, flocculating agents, swelling agents, foam stabilizers, etc. When consumed by humans, many of these gums are fermented by the microbes that inhabit the lower gastrointestinal tract (microbiome) and may influence the ecology and functions of these microscopic communities. Examples Natural gums can be classified according to their origin. They can also be classified as uncharged or ionic polymers (polyelectrolytes). Examples include (with E number E numbers ("E" stands for "Europe") are codes for substances used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naphtha
Naphtha ( or ) is a flammable liquid hydrocarbon mixture. Mixtures labelled ''naphtha'' have been produced from natural gas condensates, petroleum distillates, and the distillation of coal tar and peat. In different industries and regions ''naphtha'' may also be crude oil or refined products such as kerosene. ''Nephi'' and ''naphthar'' are sometimes used as synonyms. It is also known as Shellite in Australia. Etymology The word ''naphtha'' is from Latin and Ancient Greek (νάφθα), derived from Middle Persian ''naft'' ("wet", "naphtha"), the latter meaning of which was an assimilation from the Akkadian ''napṭu'' (see Semitic relatives such as Arabic ''nafṭ'' petroleum" Syriac ܢܰܦܬܳܐ ''naftā'') and Hebrew נֵפְט ''neft'' (meaning petroleum). In Ancient Greek, it was used to refer to any sort of petroleum or pitch. There is a hypothesis that the word is connected with the name of the Indo-Iranian god Apam Napat, which occurs in Vedic and in Avestic; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumene Process
The cumene process (cumene-phenol process, Hock process) is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR)., and independently by Heinrich Hock in 1944 This process converts two relatively cheap starting materials, benzene and propylene, into two more valuable ones, phenol and acetone. Other reactants required are oxygen from air and small amounts of a radical initiator. Most of the worldwide production of phenol and acetone is now based on this method. In 2003, nearly 7 million tonnes of phenol was produced by the cumene process.Manfred Weber, Markus Weber, Michael Kleine-Boymann "Phenol" in Ullmann's Encyclopedia of Industrial Chemistry 2004, Wiley-VCH. . In order for this process to be economical, there must also be demand for the acetone by-product as well as the phenol. Steps of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutylbenzene
Isobutylbenzene is a chemical compound with the molecular formula C10H14. It is used in the industrial manufacture of ibuprofen Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is used for treating pain, fever, and inflammation. This includes painful menstrual periods, migraines, and rheumatoid arthritis. It may also be used to close a patent ductus arte .... Isobutylbenzene is a colorless flammable liquid that is a respiratory irritant. References Alkylbenzenes C4-Benzenes {{Hydrocarbons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-butene
But-2-ene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting ''cis''/''trans''-isomerism (also known as (''E''/''Z'')-isomerism); that is, it exists as two geometric isomers ''cis''-but-2-ene ((''Z'')-but-2-ene) and ''trans-''but-2-ene ((''E'')-but-2-ene). It is a petrochemical, produced by the catalytic cracking of crude oil or the dimerization of ethylene. Its main uses are in the production of gasoline (petrol) and butadiene,. although some but-2-ene is also used to produce the solvent butanone via hydration to 2-butanol followed by oxidation. The two isomers are extremely difficult to separate by distillation because of the proximity of their boiling points (~4 °C for ''cis'' and ~1 °C for ''trans'' ) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wacker Oxidation
The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name) refers to the oxidation of ethylene to acetaldehyde in the presence of palladium(II) chloride as the catalyst. This chemical reaction was one of the first homogeneous catalysis with organopalladium chemistry applied on an industrial scale. History The Wacker reaction was first reported by Smidt et al. The development of the chemical process now known as the Wacker process began in 1956 at Wacker Chemie. At the time, many industrial compounds were produced from acetylene, derived from calcium carbide, an expensive and environmentally unfriendly technology. The construction of a new oil refinery in Cologne by Esso close to a Wacker site, combined with the realization that ethylene would be a cheaper raw-material prompted Wacker to investigate its potential uses. As part of the ensuing research effort, a reaction of ethylene and oxygen over palladium on carbon in a quest for ethylen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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