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Chloroprene
Chloroprene (IUPAC name 2-chlorobuta-1,3-diene) is a chemical compound with the molecular 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-e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Neoprene
Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene.Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion Rubbers" in Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range. Neoprene is sold either as solid rubber or in latex form and is used in a wide variety of commercial applications, such as laptop sleeves, orthopaedic braces (wrist, knee, etc.), electrical insulation, medical gloves, liquid and sheet-applied elastomeric membranes or flashings, and Motor vehicle, automotive fan belt (mechanical), belts. Production Neoprene is produced by free-radical polymerization of chloroprene. In commercial production, this polymer is prepared by Emulsion_polymerization, free radical emulsion polymerization. Polymerization is initiated us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Vinylacetylene
Vinylacetylene is the organic compound with the formula or . The colourless gas was once used in the polymer industry. It is composed of both alkyne and alkene groups and is the simplest enyne. Safety Vinylacetylene is extremely dangerous because in high enough concentrations (typically > 30 mole percent, but pressure dependent) it can auto-detonate (explode without air being present) especially at elevated pressures, such as those seen in chemical plants processing C4 hydrocarbons (hydrocarbons with 4 carbon atoms). An example of such an explosion occurred at a Union Carbide plant in Texas City in 1969. Synthesis Vinylacetylene was first synthesized by Hofmann elimination of the related quaternary ammonium salt: : It is usually synthesized by dehydrohalogenation of 1,3-dichloro-2-butene . It also arises via the dimerization of acetylene, which is catalyzed by copper(I) chloride. Dehydrogenation of 1,3-butadiene is yet another route. Application At one time, chloroprene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Butadiene
1,3-Butadiene () is the organic compound with the formula CH2=CH-CH=CH2. 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, 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] [Amazon] |
Ira Williams
Ira Williams (1894–1977) was an American chemist at DuPont's DuPont Central Research, Jackson Laboratory in New Jersey, who in the summer of 1930, together with Wallace Carothers, Arnold Collins and F. B. Downing, made commercial Neoprene possible by producing a soft, plastic form of chloroprene that could be processed by the rubber industry. Early accounts of the development credited Julius Nieuwland with synthesizing the precursor divinylacetylene. Williams' contribution was the discovery that the rheological behavior of the product could be controlled by quenching the polymerization reaction with alcohol. He won the 1946 Charles Goodyear Medal. References 20th-century American chemists American polymer scientists and engineers 1894 births 1977 deaths {{US-chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Wallace Carothers
Wallace Hume Carothers (; April 27, 1896 – April 29, 1937) was an American chemist, inventor, and the leader of organic chemistry at DuPont, who was credited with the invention of nylon. Carothers was a group leader at the DuPont Experimental Station laboratory, near Wilmington, Delaware, where most polymer research was done. Carothers was an organic chemist who, in addition to first developing nylon, also helped lay the groundwork for neoprene. After receiving his Ph.D., he taught at several universities before he was hired by DuPont to work on fundamental research. He married Helen Sweetman on February 21, 1936. Carothers had been troubled by periods of depression since his youth. Despite his success with nylon, he felt that he had not accomplished much and had run out of ideas. His unhappiness was exacerbated by the death of his sister, and on April 28, 1937, he committed suicide by drinking potassium cyanide. His daughter, Jane, was born on November 27, 1937. Educati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Elmer Keiser Bolton
Elmer Keiser Bolton (June 23, 1886 – July 30, 1968) was an American chemist and research director for DuPont, notable for his role in developing neoprene and directing the research that led to the discovery of nylon. Personal life Bolton was born in Frankford, Philadelphia, Pennsylvania, the oldest of two brothers. His father ran the furniture store on Main Street, and both he and his brother attended public school in Frankford and went on to college. Bolton went to Bucknell University in Lewisburg, Pennsylvania, and took the ''Classical Course'', receiving a B.A. degree in 1908. From there he went to Harvard University, receiving his A.M. degree in 1910 and his Ph.D. in organic chemistry in 1913. His thesis advisor was Charles Loring Jackson, and his dissertation concerned the chemistry of periodoquinones. Several other prominent contemporaries of Bolton's at Harvard Graduate School were Roger Adams, Farrington Daniels, Frank C. Whitmore, James B. Sumner and James B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Common Noun
In grammar, a noun is a word that represents a concrete or abstract thing, like living creatures, places, actions, qualities, states of existence, and ideas. A noun may serve as an object or subject within a phrase, clause, or sentence.Example nouns for: * Living creatures (including people, alive, dead, or imaginary): ''mushrooms, dogs, Afro-Caribbeans, rosebushes, Mandela, bacteria, Klingons'', etc. * Physical objects: ''hammers, pencils, Earth, guitars, atoms, stones, boots, shadows'', etc. * Places: ''closets, temples, rivers, Antarctica, houses, Uluru, utopia'', etc. * Actions of individuals or groups: ''swimming, exercises, cough, explosions, flight, electrification, embezzlement'', etc. * Physical qualities: ''colors, lengths, porosity, weights, roundness, symmetry, solidity,'' etc. * Mental or bodily states: ''jealousy, sleep, joy, headache, confusion'', etc. In linguistics, nouns constitute a lexical category (part of speech) defined according to how its members combi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Distillation
Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixture and the condensation of the vapors in a still. Distillation can operate over a wide range of pressures from 0.14 bar (e.g., ethylbenzene/ styrene) to nearly 21 bar (e.g., propylene/propane) and is capable of separating feeds with high volumetric flowrates and various components that cover a range of relative volatilities from only 1.17 ( o-xylene/ m-xylene) to 81.2 (water/ ethylene glycol). Distillation provides a convenient and time-tested solution to separate a diversity of chemicals in a continuous manner with high purity. However, distillation has an enormous environmental footprint, resulting in the consumption of approximately 25% of all industrial energy use. The key issue is that distillation operates based on phase changes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Atom
Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element. Atoms are extremely small, typically around 100 picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum mechanics, quantum effects. More than 99.94% of an atom's mass is in the nucleus. Protons hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidizing agent, oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Electronegativity#Pauling electronegativity, Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval Alchemy, alchemists, which commonly involved the heating of chloride Salt (chemistry), salts like ammonium chloride (sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and . However, the nature of fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
