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1,3-butadiene
1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vinyl groups. It is the simplest conjugated diene. Although butadiene breaks down quickly in the atmosphere, it is nevertheless found in ambient air in urban and suburban areas as a consequence of its constant emission from motor vehicles. The name butadiene can also refer to the isomer, 1,2-butadiene, which is a cumulated diene with structure H2C=C=CH−CH3. This allene has no industrial significance. History In 1863, the French chemist E. Caventou isolated butadiene from the pyrolysis of amyl alcohol. This hydrocarbon was identified as butadiene in 1886, after Henry Edward Armstrong isolated it from among the pyrolysis products of petroleum. In 1910, the Russian chemist Sergei Lebedev polymerized butadiene and obtained a material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugated Diene
In organic chemistry a diene ( ) (diolefin ( ) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alk''ene'' units, with the standard prefix ''di'' of systematic nomenclature. As a subunit of more complex molecules, dienes occur in naturally occurring and synthetic chemicals and are used in organic synthesis. Conjugated dienes are widely used as monomers in the polymer industry. Polyunsaturated fats are of interest to nutrition. Classes Dienes can be divided into three classes, depending on the relative location of the double bonds: #Cumulated dienes have the double bonds sharing a common atom. The result is more specifically called an allene. #Conjugated dienes have conjugated double bonds separated by one single bond. Conjugated dienes are more stable than other dienes because of resonance. #Unconjugated dienes have the double bonds separated by two or more single bonds. They are usually less stable tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diene
In organic chemistry a diene ( ) (diolefin ( ) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alk''ene'' units, with the standard prefix ''di'' of systematic nomenclature. As a subunit of more complex molecules, dienes occur in naturally occurring and synthetic chemicals and are used in organic synthesis. Conjugated dienes are widely used as monomers in the polymer industry. Polyunsaturated fats are of interest to nutrition. Classes Dienes can be divided into three classes, depending on the relative location of the double bonds: #Cumulated dienes have the double bonds sharing a common atom. The result is more specifically called an allene. #Conjugated dienes have conjugated double bonds separated by one single bond. Conjugated dienes are more stable than other dienes because of resonance. #Unconjugated dienes have the double bonds separated by two or more single bonds. They are usually less stable t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroprene
Chloroprene is the common name for 2-chlorobuta-1,3-diene (IUPAC name) with the chemical formula CH2=CCl−CH=CH2. Chloroprene is a colorless volatile liquid, almost exclusively used as a monomer for the production of the polymer polychloroprene, better known as neoprene, a type of synthetic rubber. History Although it may have been discovered earlier, chloroprene was largely developed by DuPont during the early 1930s, specifically with the formation of neoprene in mind. The chemists Elmer K. Bolton, Wallace Carothers, Arnold Collins and Ira Williams are generally accredited with its development and commercialisation although the work was based upon that of Julius Arthur Nieuwland, with whom they collaborated. Production Chloroprene is produced in three steps from 1,3-butadiene: (i) chlorination, (ii) isomerization of part of the product stream, and (iii) dehydrochlorination of 3,4-dichlorobut-1-ene. Chlorine adds to 1,3-butadiene to afford a mixture of 3,4-dichlorobut-1-en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprene
Isoprene, or 2-methyl-1,3-butadiene, is a common volatile organic compound with the formula CH2=C(CH3)−CH=CH2. In its pure form it is a colorless volatile liquid. Isoprene is an unsaturated hydrocarbon. It is produced by many plants and animals (including humans) and its polymers are the main component of natural rubber. C. G. Williams named the compound in 1860 after obtaining it from thermal decomposition (pyrolysis) of natural rubber; he correctly deduced the empirical formula C5H8. Natural occurrences Isoprene is produced and emitted by many species of trees (major producers are oaks, poplars, eucalyptus, and some legumes). Yearly production of isoprene emissions by vegetation is around 600 million metric tons, half from tropical broadleaf trees and the remainder primarily from shrubs. This is about equivalent to methane emissions and accounts for around one-third of all hydrocarbons released into the atmosphere. In deciduous forests, isoprene makes up approximately 80 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise from both natural and synthetic substances. Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious. Carcinogens, as mentioned, are agents in the environment capable of contributing to cancer growth. Carcinogens can be categorized into two different types: activation-dependent and activation-independent, and each nature impacts their l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthetic Rubber
A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About 32-million metric tons of rubbers are produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubber, just like natural rubber, has many uses in the automotive industry for tires, door and window profiles, seals such as O-rings and gaskets, hoses, belts, matting, and flooring. They offer a different range of physical and chemical properties, so can improve the reliability of a given product or application. Synthetic rubbers are superior to natural rubbers in two major respects, thermal stability and resistance to oils and related compounds. They are more resistant to oxidizing agents, such as oxygen and ozone which can reduce the life of products like tires. History of synthetic rubber The expanded use of bicycles, and particularly their pneumatic tires, starting in the 1890s, created increased demand for rubber. In 1909, a tea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Bock
Walter Bock (20 January 1895 – 25 October 1948)Death record Nr. 3271/Köln I for Ludwig Walter Robert Bock of Oct. 26, 1948, Landesarchiv NRW, Duisburg was a German chemist who developed styrene-butadiene copolymer by emulsion polymerization as a synthetic rubber (SBR). Early life Walter Bock was born on January 10, 1895 in the small village of Wenzen (now part of Einbeck) in the Duchy of Brunswick. He was the fourth of nine children. His father, Wilhelm Bock, was the sole teacher in Wenzen. From 1905 to 1914 Bock attended high school in Brunswick. Immediately after graduation he joined the army and served as an officer in World War I. He commanded an infantry company until he was wounded in July 1918. In October 1918 he began studying chemistry. After receiving his Ph.D. from the University of Göttingen in October 1921, Bock found employment as chemist at the Köln Rottweil AG in Premnitz. In the fall of 1924 Bock joined the Dr. Zellner laboratories in Berlin, where he to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Tschunker
Eduard Model Accessories is a Czech manufacturer of plastic models and finescale model accessories. Formed in 1989 in the city of Most, Eduard began in a rented cellar as a manufacturer of photoetched brass model components. Following the success of their early products, the company branched off into plastic models in 1993. As of 2006, Eduard's product line contained some 30 plastic kits and more than 800 individual photoetch detail sets. To the plastic modeller community at large, Eduard has become a household word in the field of photoetched parts, and their products are available worldwide. Eduard aircraft kits range from World War I to the present day. Some notable ones include: most of the famous World War I fighters are: Fokker D.VII, Pfalz D.III, Albatros D.III and the Sopwith Pup, while World War II had the: Yakovlev Yak-3, Hawker Hurricane, Spitfire and the Messerschmitt Bf 109 The Messerschmitt Bf 109 is a German World War II fighter aircraft that was, along wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Empire
The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts established by England between the late 16th and early 18th centuries. At its height it was the largest empire in history and, for over a century, was the foremost global power. By 1913, the British Empire held sway over 412 million people, of the world population at the time, and by 1920, it covered , of the Earth's total land area. As a result, its constitutional, legal, linguistic, and cultural legacy is widespread. At the peak of its power, it was described as " the empire on which the sun never sets", as the Sun was always shining on at least one of its territories. During the Age of Discovery in the 15th and 16th centuries, Portugal and Spain pioneered European exploration of the globe, and in the process established larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sergei Vasilyevich Lebedev
Sergei Vasilievich Lebedev (russian: Сергей Васильевич Лебедев; 13 July 1874 – 2 May 1934) was a Russian/Soviet chemist and the inventor of polybutadiene synthetic rubber, the first commercially viable and mass-produced type of synthetic rubber. Biography Lebedev was born in 1874 in Lublin and went to school in Warsaw. In 1900, he graduated from St. Petersburg University and found work at the Petersburg Margarine Factory. Starting in 1902, Lebedev moved from university to university in Russia, starting at the Saint-Petersburg Institute for Railroad Engineering. In 1904, he returned to St. Petersburg University to work under Alexey Favorsky (Stalin Prize, 1941, for contributions to the manufacture of synthetic rubber). In 1905, he married his second wife, the artist Anna Ostroumova-Lebedeva. In 1915, Lebedev was appointed Professor at the Women's Pedagogical Institute in St. Petersburg. After 1916, he was a Professor of the Saint Petersbur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Edward Armstrong
Henry Edward Armstrong FRS FRSE (Hon) (6 May 1848 – 13 July 1937) was a British chemist. Although Armstrong was active in many areas of scientific research, such as the chemistry of naphthalene derivatives, he is remembered today largely for his ideas and work on the teaching of science. Armstrong's acid is named for him. Life and work Armstrong was born the son of Richard Armstrong, a commission agent and importer, and Mary Ann Biddle. He lived most of his life in Lewisham, a suburb of London. After finishing school in 1864 at age 16, he spent a winter in Gibraltar, with a relative, for health reasons. In the spring of 1865, Armstrong returned to England and entered the Royal College of Chemistry in London, now the department of chemistry at Imperial College. Chemical training in those days was not lengthy, and at the age of 18 he was selected by Edward Frankland to assist in devising methods of determining organic impurities in sewage. Armstrong pursued further studies un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyl Alcohol
An amyl alcohol is any of eight alcohols with the formula C5H12O. A mixture of amyl alcohols (also called amyl alcohol) can be obtained from fusel alcohol. Amyl alcohol is used as a solvent and in esterification, by which is produced amyl acetate and other important products. The name ''amyl alcohol'' without further specification applies to the normal (straight-chain) form, 1-pentanol. These are the 8 alcohols that are structural isomers with molecular formula C5H12O: : Three of these alcohols, 2-methyl-1-butanol, 2-pentanol, and 3-methyl-2-butanol (methyl isopropyl carbinol), are therefore optically active Optical rotation, also known as polarization rotation or circular birefringence, is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Circul .... The most important amyl alcohol is isoamyl alcohol, the chief one generated by fermentation in the production of alcohol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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