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Terephthalate Esters
Terephthalic acid is an organic compound with chemical formula, formula C6H4(CO2H)2. This white solid is a commodity chemical compound, chemical, used principally as a precursor to the polyester Polyethylene terephthalate, PET, used to make clothing and plastic bottles. Several million tons are produced annually. The common name is derived from the turpentine-producing tree ''Pistacia terebinthus'' and phthalic acid. Terephthalic acid is also used in the production of Polybutylene terephthalate, PBT plastic (polybutylene terephthalate). History Terephthalic acid was first isolated (from turpentine) by the French chemist Amédée Cailliot (1805–1884) in 1846. Terephthalic acid became industrially important after World War II. Terephthalic acid was produced by oxidation of p-Xylene, ''p''-xylene with 30-40% nitric acid. Air oxidation of ''p''-xylene gives P-Toluic acid, ''p''-toluic acid, which resists further air-oxidation. Esterification of ''p''-toluic acid to methyl p-toluate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Handbook Of Chemistry And Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 105th edition, published in 2024. It is known colloquially among chemists as the "Rubber Bible", as CRC originally stood for "Chemical Rubber Company". As late as the 1962–1963 edition (3604 pages), the ''Handbook'' contained myriad information for every branch of science and engineering. Sections in that edition include: Mathematics, Properties and Physical Constants, Chemical Tables, Properties of Matter, Heat, Hygrometric and Barometric Tables, Sound, Quantities and Units, and Miscellaneous. ''Mathematical Tables from Handbook of Chemistry and Physics'' was originally published as a supplement to the handbook up to the 9th edition (1952); afterwards, the 10th edition (1956) was published separately as '' CRC Standard Mathematical Tables''. Earlier editions included sections such as "Antidotes of Poisons", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turpentine
Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthine, terebenthene, terebinthine and, colloquially, turps) is a fluid obtainable by the distillation of resin harvested from living trees, mainly pines. Principally used as a specialized solvent, it is also a source of material for Organic synthesis, organic syntheses. Turpentine is composed of terpenes, primarily the monoterpenes alpha-Pinene, alpha- and beta-Pinene, beta-pinene, with lesser amounts of carene, camphene, limonene, and terpinolene.Kent, James A. ''Riegel's Handbook of Industrial Chemistry'' (Eighth Edition) Van Nostrand Reinhold Company (1983) p.569 Nowadays, turpentine is rarely the product of distillation of pine resin, but is a byproduct of pulping. Pulping is achieved by two processes, the Kraft process and the sulfite process. The turpentines obtained from these two processes differ in their chemical compositions. The sulfite process gives a product that is rich in cymene, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese
Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent, as a rubber additive, and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese is commonly found in labo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt
Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, somewhat brittle, gray metal. Cobalt-based blue pigments (cobalt blue) have been used since antiquity for jewelry and paints, and to impart a distinctive blue tint to glass. The color was long thought to be due to the metal bismuth. Miners had long used the name ''kobold ore'' (German language, German for ''goblin ore'') for some of the blue pigment-producing minerals. They were so named because they were poor in known metals and gave off poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), which was ultimately named for the ''kobold''. Today, some cobalt is produced sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation P Xylene
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * Atom transfer – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * Atom transfer – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by 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. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethyl Terephthalate
Dimethyl terephthalate (DMT) is an organic compound with the formula . It is the ester, diester formed from terephthalic acid and methanol. It is a white solid that melts to give a distillable colourless liquid. Production Dimethyl terephthalate (DMT) has been produced in a number of ways. Conventionally, and still of commercial value, is the direct esterification of terephthalic acid. Alternatively, it can be prepared by alternating oxidation and methyl-esterification steps from p-xylene, ''para''-xylene via methyl p-toluate, methyl ''para''-toluate (PT). Dimethyl terephthalate by the Witten process The method for the production of DMT from ''p''-xylene (PX) and methanol consists of a multistep process involving both oxidation and esterification. A mixture of p-xylene (PX) and methyl ''p''-toluate is oxidized with air in the presence of cobalt and manganese catalysts. The acid mixture resulting from the oxidation is esterified with methanol to produce a mixture of esters. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl P-toluate
Methyl ''p''-toluate is the organic compound with the formula . It is a waxy white solid that is soluble in common organic solvents. It is the methyl ester of ''p''-toluic acid. Methyl ''p''-toluate per se is not particularly important but is an intermediate in some routes to dimethyl terephthalate Dimethyl terephthalate (DMT) is an organic compound with the formula . It is the ester, diester formed from terephthalic acid and methanol. It is a white solid that melts to give a distillable colourless liquid. Production Dimethyl terephthalat ..., a commodity chemical.{{cite journal, title=p-Xylene Oxidation to Terephthalic Acid: A Literature Review Oriented toward Process Optimization and Development, author1=Tomas, Rogerio A. F. , author2=Bordado, Joao C. M. , author3=Gomes, Joao F. P. , journal=Chemical Reviews, year=2013, volume=113, issue=10 , pages=7421–69 , doi=10.1021/cr300298j , pmid=23767849 References Methyl esters Benzoate esters Commodity chemicals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-Toluic Acid
''p''-Toluic acid (4-methylbenzoic acid) is a substituted benzoic acid with the formula CH3C6H4CO2H. It is a white solid that is poorly soluble in water but soluble in acetone. A laboratory route to ''p''-toluic acid involves oxidation of p-cymene with nitric acid. Role in production of terephthalic acid ''p''-Toluic acid is an intermediate in the conversion of ''p''-xylene to terephthalic acid, a commodity chemical used in the manufacture of polyethylene terephthalate. It is generated both by the oxidation of ''p''-xylene as well as the hydrogenolysis of 4-carboxybenzaldehyde. In related processes it is converted to methyl p-toluate Methyl ''p''-toluate is the organic compound with the formula . It is a waxy white solid that is soluble in common organic solvents. It is the methyl ester of ''p''-toluic acid. Methyl ''p''-toluate per se is not particularly important but is ..., which is oxidized to monomethyl terephthalate. See also * ''o''-Toluic acid * ''m'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as synthetic dyes and medicines (e.g. metronidazole). Nitric acid is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
