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Delrin (Company)
Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. Short-chained POM (chain length between 8 and 100 repeating units) is also better known as paraformaldehyde (PFA). As with many other synthetic polymers, polyoxymethylenes are produced by different chemical firms with slightly different formulas and sold as Delrin, Kocetal, Ultraform, Celcon, Ramtal, Duracon, Kepital, Polypenco, Tenac and Hostaform. POM is characterized by its high strength, hardness and rigidity to −40 °C. POM is intrinsically opaque white because of its high crystalline composition but can be produced in a variety of colors. POM has a density of 1.410–1.420g/cm3. Typical applications for injection-molded POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, fasteners, g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keck Clips
Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may be rapidly fitted together to reflux a reaction mixture. This is a large improvement compared with older methods of custom-made glassware, which was time-consuming and expensive, or the use of less chemical resistant and heat resistant corks or rubber bungs and glass tubes as joints, which took time to prepare as well. One of the glassware items to be joined would have an ''inner'' (or male) ''joint'' with the ground glass surface facing outward and the other would have an ''outer'' (or female) ''joint'' of a correspondingly fitting taper with the ground glass surface facing inward. To connect the hollow inner spaces of the glassware components, ground glass joints are hollow on the inside and open at the ends, except for stoppers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DuPont
Dupont, DuPont, Du Pont, duPont, or du Pont may refer to: People * Dupont (surname) Dupont, also spelled as DuPont, duPont, Du Pont, or du Pont is a French surname meaning "of the bridge", historically indicating that the holder of the surname resided near a bridge. , the name was the fourth most popular surname in Belgium, and , i ..., a surname of French origin * Du Pont family, one of the wealthiest families in the United States Companies * DuPont, one of the world's largest chemical companies * Du Pont Motors, a marine engine and automobile manufacturer from 1919 to 1931 * Dupont Brewery, a brewery in Belgium Places in the United States * Dupont, Colorado, an unincorporated community * Du Pont, Georgia, a town * Dupont, Indiana, a town * Dupont, Pointe Coupee Parish, Louisiana, an unincorporated community * Dupont, Ohio, a village * Dupont, Pennsylvania, a borough * Dupont, Tennessee, a community * DuPont, Washington, a city * Dupont, Wisconsin, a town * DuPont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemiacetal
In organic chemistry, a hemiacetal is a functional group the general formula , where is a hydrogen atom or an organic substituent. They generally result from the nucleophilic Addition reaction, addition of an Alcohol (chemistry), alcohol (a compound with at least one hydroxy group) to an aldehyde () or a ketone () under acidic conditions. The addition of an alcohol to a ketone is more commonly referred to as a hemiketal. Common examples of hemiacetals include cyclic Monosaccharide, monosaccharides. Hemiacetals have use as a protecting group and in synthesizing oxygenated heterocycles like Tetrahydrofuran, tetrahydrofurans. Nomenclature According to the IUPAC definition of a hemiacetal, the R1 and R2 groups may or may not be hydrogen. In a hemiketal, both of these R-groups must not be hydrogen. Thus, hemiketals are regarded as a subclass of hemiacetals. The prefix ''hemi,'' meaning half, refers to the one alcohol added to the carbonyl group. This is half of the required alcohols to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formaldehyde
Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as aqueous solutions (formalin), which consists mainly of the hydrate CH2(OH)2. It is the simplest of the aldehydes (). As a precursor to many other materials and chemical compounds, in 2006 the global production of formaldehyde was estimated at 12 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Formaldehyde also occurs naturally. It is derived from the degradation of serine, dimethylglycine, and lipids. Demethylases act by converting N-methyl groups to formaldehyde. Formaldehyde is classified as a group 1 carcinogen and can cause respiratory and skin irritation upon exposure. Forms Formaldehyde is more complicated than many simple carbon compounds in that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anhydrous
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achieve perfect dryness; anhydrous compounds gradually absorb water from the atmosphere so they must be stored carefully. Solids Many salts and solids can be dried using heat, or under vacuum. Desiccators can also be used to store reagents in dry conditions. Common desiccants include phosphorus pentoxide and silica gel. Chemists may also require dry glassware for sensitive reactions. This can be achieved by drying glassware in an oven, by flame, or under vacuum. Dry solids can be produced by freeze-drying, which is also known as lyophilization. Liquids or solvents In many cases, the presence of water can prevent a reaction from happening, or cause undesirable products to form. To prevent this, anhydrous solvents must be used when perform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hessen
Hesse or Hessen ( ), officially the State of Hesse (), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt, which is also the country's principal financial centre. Two other major historic cities are Darmstadt and Kassel. With an area of 21,114.73 square kilometers and a population of over six million, it ranks seventh and fifth, respectively, among the sixteen German states. Frankfurt Rhine-Main, Germany's second-largest metropolitan area (after Rhine-Ruhr), is mainly located in Hesse. As a cultural region, Hesse also includes the area known as Rhenish Hesse (Rheinhessen) in the neighboring state of Rhineland-Palatinate. Etymology The German name , like the names of other German regions ( " Swabia", " Franconia", "Bavaria", "Saxony"), derives from the dative plural form of the name of the inhabitants or eponymous tribe, the Hessians (, singular ). The geographical name represents a short equivalent of the older compound name ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelsterbach
Kelsterbach () is a town in Groß-Gerau district in Hessen, Germany, part of the Frankfurt Rhein-Main urban area. It is located on Frankfurt's southwestern outskirts at a bend on the left bank of the river Main, right where a small brook, called the Kelster (''Bach'' means "brook" in German) joins the river. After the Frankfurt–Mainz railway line was built, this formerly mostly agricultural village was transformed by the great number of large factories that located here, bringing along with them a great upswing in the town's population. In the decades following the Second World War, many businesses that were related to Frankfurt International Airport moved to the town. Kelsterbach is home to 16,565 people (). The town is an important centre for logistical service providers and chemical production. In 1952, it acquired the status of "town." Geography Location The town lies on the south side of the Main and west of the Frankfurt City Forest. The original village centre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoechst AG
Hoechst AG () was a German chemicals, later life sciences, company that became Aventis Deutschland after its merger with France's Rhône-Poulenc S.A. in 1999. With the new company's 2004 merger with Sanofi-Synthélabo, it became a subsidiary of the resulting Sanofi-Aventis pharmaceuticals group. History The company was founded in 1863 as "Teerfarbenfabrik Meister, Lucius & Co." in Höchst, near Frankfurt and changed its name some years later to "Teerfarbenfabrik Meister Lucius & Brüning". In 1880, it became a stock company "Farbwerke vorm. Meister Lucius & Brüning AG". For the international market the name was simplified to "Farbwerke Hoechst AG". Until 1925, the Hoechst AG was independent. In 1916, the Hoechst AG was one of the co-founders of IG Farben, an advocacy group of Germany's chemicals industry to gain industrial power during and after World War I. In 1925, IG Farben turned from an advocacy group into the well-known conglomerate. World War II Various Hoechs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankfurt
Frankfurt am Main () is the most populous city in the States of Germany, German state of Hesse. Its 773,068 inhabitants as of 2022 make it the List of cities in Germany by population, fifth-most populous city in Germany. Located in the foreland of the Taunus on its namesake Main (river), Main, it forms a continuous conurbation with Offenbach am Main; Frankfurt Rhein-Main Regional Authority, its urban area has a population of over 2.7 million. The city is the heart of the larger Rhine-Main metropolitan region, which has a population of more than 5.8 million and is Germany's Metropolitan regions in Germany, second-largest metropolitan region after the Rhine-Ruhr metropolitan region, Rhine-Ruhr region and the List of EU metropolitan regions by GDP#2021 ranking of top four German metropolitan regions, fourth largest metropolitan region by GDP in the European Union (EU). Frankfurt is one of the ''de facto'' four main capitals of the European Union (alongside Brussels, Luxembourg Cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celanese
Celanese Corporation, formerly known as Hoechst Celanese, is an American technology and specialty materials company headquartered in Irving, Texas. It is a Fortune 500 corporation. The company is the world's leading producer of acetic acid, producing about 1.95 million tonnes per year, representing approximately 20% of global production. Celanese is also the world's largest producer of vinyl acetate monomer (VAM). Celanese operates 25 production plants and six research centers in 11 countries, mainly in North America, Europe, and Asia. The company owns and operates the world's three largest acetic acid plants: one in the Clear Lake area of Pasadena, Texas, one on Jurong Island in Singapore, and a third in Nanjing, China. History In 1918, the American Cellulose & Chemical Manufacturing Company (known as Amcelle) was founded in New York City by Swiss chemist Camille Dreyfus. The American Cellulose and Chemical Manufacturing Co. Ltd plant in Cumberland, Maryland, was set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkersburg, West Virginia
Parkersburg is a city in Wood County, West Virginia, United States, and its county seat. Located at the confluence of the Ohio River, Ohio and Little Kanawha River, Little Kanawha rivers, it is the state's List of municipalities in West Virginia, fourth-most populous city and the center of the Parkersburg–Vienna metropolitan area. The city's population was 29,749 at the 2020 United States census, 2020 census, and its metro population was 89,490. The city is about south of Marietta, Ohio. History Settlers at first named the city Newport when they settled it in the late 18th century following the American Revolutionary War. A town section was laid out on land granted to Alexander Parker for his Revolutionary War service. Virginia made grants of land to veterans for their war service. The title conflicts between Parker and the city planners of Newport were settled in 1809 in favor of his heirs. The town was renamed Parkersburg in 1810. It was chartered by the Virginia General Ass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetic Anhydride
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula, formula . Commonly abbreviated , it is one the simplest organic acid anhydride, anhydrides of a carboxylic acid and is widely used in the production of cellulose acetate as well as a reagent in organic synthesis. It is a colorless liquid that smells strongly of acetic acid, which is formed by its reaction with moisture in the air. Structure and properties Acetic anhydride, like most organic acid anhydrides, is a flexible molecule with a nonplanar structure. The C=O and C-O distances are 1.19 and 1.39 Å. The Pi bond, pi system linkage through the central oxygen offers very weak resonance stabilization compared to the dipole, dipole-dipole repulsion between the two carbonyl oxygens. The energy barriers to bond rotation between each of the optimal aplanar conformations are quite low. Production Acetic anhydride was first synthesized in 1852 by the French chemist Charles Frédéric Gerhardt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
