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Vinylchloride
Vinyl chloride is an organochloride with the formula H2C =CHCl. It is also called vinyl chloride monomer (VCM) or chloroethene. It is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC). Vinyl chloride is a colourless flammable gas that has a sweet odor and is carcinogenic. Vinyl chloride monomer is among the top twenty largest petrochemicals (petroleum-derived chemicals) in world production. The United States remains the largest vinyl chloride manufacturing region because of its low-production-cost position in chlorine and ethylene raw materials. China is also a large manufacturer and one of the largest consumers of vinyl chloride. It can be formed in the environment when soil organisms break down chlorinated solvents. Vinyl chloride that is released by industries or formed by the breakdown of other chlorinated chemicals can enter the air and drinking water supplies. Vinyl chloride is a common contaminant found near landfills. Before the 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyvinyl Chloride
Polyvinyl chloride (alternatively: poly(vinyl chloride), colloquial: vinyl or polyvinyl; abbreviated: PVC) is the world's third-most widely produced synthetic polymer of plastic (after polyethylene and polypropylene). About 40 million tons of PVC are produced each year. PVC comes in rigid (sometimes abbreviated as RPVC) and flexible forms. Rigid PVC is used in construction for pipes, doors and windows. It is also used in making plastic bottles, packaging, and bank or membership cards. Adding plasticizers makes PVC softer and more flexible. It is used in plumbing, electrical cable insulation, flooring, signage, phonograph records, inflatable products, and in rubber substitutes. With cotton or linen, it is used in the production of canvas. Polyvinyl chloride is a white, brittle solid. It is soluble in ketones, chlorinated solvents, dimethylformamide, THF and DMAc. Discovery PVC was synthesized in 1872 by German chemist Eugen Baumann after extended investigation and experimenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochloride
Organochlorine chemistry is concerned with the properties of organochlorine compounds, or organochlorides, organic compounds that contain one or more carbon–chlorine bonds. The chloroalkane class (alkanes with one or more hydrogens substituted by chlorine) includes common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious. Organochlorides such as trichloroethylene, tetrachloroethylene, dichloromethane and chloroform are commonly used as solvents and are referred to as "chlorinated solvents". Physical and chemical properties Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. They have hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerosol Spray
Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles. It comprises a can or bottle that contains a payload, and a propellant under pressure. When the container's valve is opened, the payload is forced out of a small opening and emerges as an aerosol or mist. History There is a high chance that the concepts of aerosol go as far back as 1790.Bellis, MarThe History of Aerosol Spray Cans/ref> The first aerosol spray can patent was granted in Oslo in 1927 to Erik Rotheim, a Norwegian chemical engineer,Norwegian Patent No. 46613, issued on November 23, 1926 and a United States patent was granted for the invention in 1931. — Method and Means for the Atomizing or Distribution of Liquid or Semiliquid Materials, issued April 7, 1931 The patent rights were sold to a United States company for 100,000 Norwegian kroner. The Norwegian Postal Service, Posten Norge, celebrated the invention by issuing a stamp in 1998. In 1939, American Julian S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalational Anaesthetic
An inhalational anesthetic is a chemical compound possessing general anesthetic properties that is delivered via inhalation. They are administered through a face mask, laryngeal mask airway or tracheal tube connected to an anesthetic vaporiser and an anesthetic delivery system. Agents of significant contemporary clinical interest include volatile anesthetic agents such as isoflurane, sevoflurane and desflurane, as well as certain anesthetic gases such as nitrous oxide and xenon. List of inhalational anaesthetic agents Currently-used agents * Desflurane * Isoflurane * Nitrous oxide * Sevoflurane * Xenon Previously-used agents Although some of these are still used in clinical practice and in research, the following anaesthetic agents are primarily of historical interest in developed countries: * Acetylene * Chloroethane (ethyl chloride) * Chloroform * Cryofluorane * Cyclopropane * Diethyl ether * Divinyl ether * Enflurane * Ethylene * Fluroxene * Halothane (still widely use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroethane
Chloroethane, commonly known as ethyl chloride, is a chemical compound with chemical formula CH3CH2Cl, once widely used in producing tetraethyllead, a gasoline additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet odor. Ethyl chloride was first synthesized by Basil Valentine by reacting ethanol and hydrochloric acid in 1440. Glauber made it in 1648 by reacting ethanol and zinc chloride. Production Chloroethane is produced by hydrochlorination of ethylene: :C2H4 + HCl → C2H5Cl At various times in the past, chloroethane has also been produced from ethanol and hydrochloric acid, from ethane and chlorine, or from ethanol and phosphorus trichloride, but these routes are no longer economical. Some chloroethane is generated as a byproduct of polyvinyl chloride production. Uses Chloroethane is an inexpensive ethylating agent. It reacts with aluminium metal to give ethylaluminium sesquichloride, a precursor to polymers and other useful organoalumini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Justus Von Liebig
Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a Germans, German scientist who made major contributions to the theory, practice, and pedagogy of chemistry, as well as to agricultural and biology, biological chemistry; he is considered one of the principal founders of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the most outstanding chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and minerals as essential plant nutrients, and his popularization of the law of the minimum, which states that plant growth is limited by the scarcest nutrient resource, rather than the total amount of resources available. He also developed a manufacturing process for Meat extract, beef extracts, and with his consent a company, called Liebig Extract of Meat Company, was founded to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henri Victor Regnault
Henri Victor Regnault (21 July 1810 – 19 January 1878) was a French chemist and physicist best known for his careful measurements of the thermal properties of gases. He was an early thermodynamicist and was mentor to William Thomson in the late 1840s. He never used his first given name, and was known throughout his lifetime as Victor Regnault. Biography Born in Aix-la-Chapelle in 1810 (modern Aachen, Germany and at that time under French rule), he moved to Paris at the age of eight, following the death of his parents. There, he worked for an upholstery firm until he was eighteen. In 1830, he was admitted to the École Polytechnique, and in 1832 he graduated from the École des mines. Working under Justus von Liebig at Gießen, Regnault distinguished himself in the nascent field of organic chemistry by synthesizing several chlorinated hydrocarbons (e.g. vinyl chloride in 1835, dichloromethane and perchloroethylene in 1839, 1,1,1-Trichloroethane in 1838 or 1840), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centers For Disease Control And Prevention
The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency under the United States Department of Health and Human Services, Department of Health and Human Services (HHS), and is headquartered in Atlanta, Georgia. The CDC's current nominee for director is Susan Monarez. She became acting director on January 23, 2025, but stepped down on March 24, 2025 when nominated for the director position. On May 14, 2025, Robert F. Kennedy Jr. stated that lawyer Matthew Buzzelli is acting CDC director. However, the CDC web site does not state the acting director's name. The agency's main goal is the protection of public health and safety through the control and prevention of disease, injury, and disability in the US and worldwide. The CDC focuses national attention on developing and applying disease control and prevention. It e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Library Of Medicine
The United States National Library of Medicine (NLM), operated by the United States federal government, is the world's largest medical library. Located in Bethesda, Maryland, the NLM is an institute within the National Institutes of Health. Its collections include more than seven million books, journals, technical reports, manuscripts, microfilms, photographs, and images on medicine and related sciences, including some of the world's oldest and rarest works. the acting director of the NLM was Stephen Sherry. History The precursor of the National Library of Medicine, established in 1836, was the Library of the Surgeon General's Office, a part of the office of the Surgeon General of the United States Army. The Armed Forces Institute of Pathology and its Medical Museum were founded in 1862 as the Army Medical Museum. Throughout their history the Library of the Surgeon General's Office and the Army Medical Museum often shared quarters. From 1866 to 1887, they were ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Dichloroethane
The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vinyl chloride, which is used to make polyvinyl chloride (PVC) pipes, furniture and automobile upholstery, wall coverings, housewares, and automobile parts. 1,2-Dichloroethane is also used generally as an intermediate for other organic chemical compounds, and as a solvent. It forms azeotropes with many other solvents, including water (at a boiling point of ) and other chlorocarbons. History In 1794, physician Jan Rudolph Deiman, merchant Adriaan Paets van Troostwijk, chemist Anthoni Lauwerenburg, and botanist Nicolaas Bondt, under the name of Society of Dutch Chemists (), were the first to produce 1,2-dichloroethane from olefiant gas (oil-making gas, ethylene) and chlorine gas. Although the ''Gezelschap'' in practice did not do much in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
