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Methyl Methacrylate
Methyl methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA). Production and properties Given the scale of production, many methods have been developed starting from diverse two- to four-carbon precursors.. Two principal routes appear to be commonly practiced. Cyanohydrin route The compound is manufactured by several methods, the principal one being the acetone cyanohydrin (ACH) route. ACH is produced by condensation of acetone and hydrogen cyanide. The cyanohydrin is hydrolyzed in the presence of sulfuric acid to a sulfate ester of the methacrylamide. Methanolysis of this ester gives ammonium bisulfate and MMA. Although widely used, the ACH route coproduces substantial amounts of ammonium sulfate. :(CH3)2CO + HCN → (CH3)2C(OH)CN :(CH3)2C(OH)CN + H2SO4 → (CH3)2C(OSO3H)C(O)NH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poly(methyl Methacrylate)
Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, Astariglas, Lucite, Perclax, and Perspex, among several others ( see below). This plastic is often used in sheet form as a lightweight or shatter-resistant alternative to glass. It can also be used as a casting resin, in inks and coatings, and for many other purposes. Although not a type of familiar silica-based glass, the substance, like many thermoplastics, is often technically classified as a type of glass, in that it is a non-crystalline vitreous substance—hence its occasional historic designation as ''acrylic glass''. Chemically, it is the synthetic polymer of methyl methacrylate. It was developed in 1928 in several different laboratories by many chemists, such as William Chalmers, Otto Röhm, and Walter Bauer, and first brough ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poise (unit)
The poise (symbol P; ) is the unit of dynamic viscosity (absolute viscosity) in the centimetre–gram–second system of units (CGS). It is named after Jean Léonard Marie Poiseuille (see Hagen–Poiseuille equation). The centipoise (1 cP = 0.01 P) is more commonly used than the poise itself. Dynamic viscosity has dimension \mathrm. 1~\text = 0.1~\text^ \text \text^ = 1~\text^ \text \text^ = 1~\text \text \text^. The analogous unit in the International System of Units is the pascal-second (Pa⋅s): 1~\text \text = 1~\text \text \text^ = 1~\text^ \text \text^ = 10~\text. The poise is often used with the metric prefix ''centi-'' because the viscosity of water at 20 °C (standard conditions for temperature and pressure) is almost exactly 1 centipoise. A centipoise is one hundredth of a poise, or one millipascal-second (mPa⋅s) in SI units (1 cP = 10−3 Pa⋅s = 1 mPa⋅s). The CGS symbol for the centipoise is cP. The abbreviations cps, ... [...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 isobuty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palladium Acetate
Palladium(II) acetate is a chemical compound of palladium described by the formula d(O2CCH3)2sub>n, abbreviated d(OAc)2sub>n. It is more reactive than the analogous platinum compound. Depending on the value of n, the compound is soluble in many organic solvents and is commonly used as a catalyst for organic reactions. Structure With a 1:2 stoichiometric ratio of palladium atoms and acetate ligands, the compound exists as molecular and polymeric forms with the trimeric form being the dominant form in the solid state and in solution. Pd achieves approximate square planar coordination in both forms. As prepared by Geoffrey Wilkinson and coworkers in 1965 and later characterized by Skapski and Smart in 1970 by single crystal X-ray diffraction, palladium(II) acetate is a red-brown solid that crystallizes as monoclinic plates. It has a trimeric structure, consisting of an equilateral triangle of Pd atoms each pair of which is bridged with two acetate groups in a butterfly conforma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reppe Chemistry
Walter Julius Reppe (29 July 1892 in Göringen – 26 July 1969 in Heidelberg) was a German chemist. He is notable for his contributions to the chemistry of acetylene. Education and career Walter Reppe began his study of the natural sciences University of Jena in 1911. Interrupted by the First World War, he obtained his doctorate in Munich in 1920. In 1921, Reppe worked for BASF's main laboratory. From 1923, he worked on the catalytic dehydration of formamide to prussic acid in the indigo laboratory, developing this procedure for industrial use. In 1924, he left research for 10 years, only resuming it in 1934. Acetylene chemistry Reppe began his interest in acetylene in 1928. Acetylene is a gas which can take part in many chemical reactions. However, it is explosive and accidents often occurred. Because of this danger, small quantities of acetylene were used at a time, and always without high pressures. In fact, it was forbidden to compress acetylene over 1.5 bar at BASF. To ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroformylation
Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon double bond. This process has undergone continuous growth since its invention: Production capacity reached 6.6×106 tons in 1995. It is important because aldehydes are easily converted into many secondary products. For example, the resulting aldehydes are hydrogenated to alcohols that are converted to detergents. Hydroformylation is also used in speciality chemicals, relevant to the organic synthesis of fragrances and drugs. The development of hydroformylation is one of the premier achievements of 20th-century industrial chemistry. The process entails treatment of an alkene typically with high pressures (between 10 and 100 atmospheres) of carbon monoxide and hydrogen at temperatures between 40 and 200 °C. In one variation, formald ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium Oxide
Caesium oxide (IUPAC name), or cesium oxide, describes inorganic compounds composed of caesium and oxygen. Several binary (containing only Cs and O) oxides of caesium are known.. Caesium oxide may refer to: * Caesium suboxides (Cs7O, Cs4O, and Cs11O3) * Caesium monoxide (Cs2O, the most common oxide) * Caesium peroxide (Cs2O2) * Caesium sesquioxide (Cs2O3) * Caesium superoxide (CsO2) * Caesium ozonide Caesium ozonide (CsO3) is an oxygen-rich compound of caesium. It is an ozonide, meaning it contains the ozonide anion (O3−). It can be formed by reacting ozone with caesium superoxide: :CsO2 + O3 -> CsO3 + O2 The compound will react strongly ... (CsO3) References {{Authority control Caesium compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formaldehyde
Formaldehyde ( , ) ( systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes (). The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Forms Formaldehyde is more complicated than many simple carbon compounds in that it adopts several diverse forms. These compounds can often be used interchangeably and can be interconverted. *Molecular f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Propionate
Methyl propionate, also known as methyl propanoate, is an organic compound with the molecular formula CH3CH2CO2CH3. It is a colorless liquid with a fruity, rum-like odor. Preparation Methyl propionate can be prepared by esterification of propionic acid with methanol. Industrially, it is prepared by carboalkoxylation, i.e., the reaction of ethylene with carbon monoxide and methanol in the presence of a catalyst: :C2H4 + CO + MeOH → MeO2CCH2CH3 The reaction is catalyzed by nickel carbonyl and palladium(0) complexes.(mayth and yafs)Scott D. Barnicki "Synthetic Organic Chemicals" in Handbook of Industrial Chemistry and Biotechnology edited by James A. Kent, New York : Springer, 2012. 12th ed. . Uses Condensation of Methyl propionate with formaldehyde followed by dehydration yields methyl methacrylate: :MeO2CCH2CH3 + CH2O → MeO2CCH(CH2OH)CH3 :MeO2CCH(CH2OH)CH3 → MeO2CC(=CH2)CH3 Methyl propionate is used as a solvent for cellulose nitrate and lacquers, and as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboalkoxylation
In industrial chemistry, carboalkoxylation is a process for converting alkenes to esters. This reaction is a form of carbonylation. A closely related reaction is hydrocarboxylation, which employs water in place of alcohols A commercial application is the carbomethoxylation of ethylene to give methyl propionate: :C2H4 + CO + MeOH → MeO2CC2H5 The process is catalyzed by Pd 6H4(CH2PBu-t)2sub>2. Under similar conditions, other Pd-diphosphines catalyze formation of polyethyleneketone. Methyl propionate ester is a precursor to methyl methacrylate, which is used in plastics and adhesives. Carboalkoxylation has been incorporated into various telomerization schemes. For example carboalkoxylation has been coupled with the dimerization of 1,3-butadiene. This step produces a doubly unsaturated C9-ester: :2CH2=CH-CH=CH2 + CO + CH3OH → CH2=CH(CH2)3CH=CHCH2CO2CH3 Hydroesterification Related to carboalkoxylation is hydroesterification, the insertion of alkenes and alkynes int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydrogenation
In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At its simplest, it is useful way of converting alkanes, which are relatively inert and thus low-valued, to olefins, which are reactive and thus more valuable. Alkenes are precursors to aldehydes (), alcohols (), polymers, and aromatics. As a problematic reaction, the fouling and inactivation of many catalysts arises via coking, which is the dehydrogenative polymerization of organic substrates. Enzymes that catalyze dehydrogenation are called dehydrogenases. Heterogeneous catalytic routes Styrene Dehydrogenation processes are used extensively to produce aromatics in the petrochemical industry. Such processes are highly endothermic and require temperatures of 500 °C and above. Dehydrogenation also converts saturated fats to unsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutyric Acid
Isobutyric acid, also known as 2-methylpropanoic acid or isobutanoic acid, is a carboxylic acid with structural formula ( CH3)2CH COOH. It is an isomer of ''n''-butyric acid. It is classified as a short-chain fatty acid. Deprotonation or esterification gives derivatives called isobutyrates. Isobutyric acid is a colorless liquid with a somewhat unpleasant odor. It is soluble in water and organic solvents. It is found naturally in carobs (''Ceratonia siliqua''), in vanilla, and in the root of ''Arnica dulcis'', and as an ethyl ester in croton oil. Production Isobutyric acid is manufactured by the oxidation of isobutyraldehyde, which is a byproduct of the hydroformylation of propylene. It can also be prepared by the high pressure hydrocarboxylation (Koch reaction) from propylene: :CH3CH=CH2 + CO + H2O → (CH3)2CHCO2H Isobutyric acid can also be manufactured commercially using engineered bacteria with a sugar feedstock. Laboratory methods Many routes are known includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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