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Polyacrylonitrile
Polyacrylonitrile (PAN) is a synthetic, semicrystalline organic polymer resin, with the linear formula (CH2CHCN)n. Almost all PAN resins are copolymers with acrylonitrile as the main monomer. PAN is used to produce large variety of products including ultra filtration membranes, hollow fibers for reverse osmosis, fibers for textiles, and oxidized PAN fibers. PAN fibers are the chemical precursor of very high-quality carbon fiber. PAN is first thermally oxidized in air at 230 °C to form an oxidized PAN fiber and then carbonized above 1000 °C in inert atmosphere to make carbon fibers found in a variety of both high-tech and common daily applications such as civil and military aircraft primary and secondary structures, missiles, solid propellant rocket motors, pressure vessels, fishing rods, tennis rackets and bicycle frames. It is a component repeat unit in several important copolymers, such as styrene-acrylonitrile (SAN) and acrylonitrile butadiene styrene (ABS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrylonitrile
Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid. It has a pungent odor of garlic or onions. Its molecular structure consists of a vinyl group () linked to a nitrile (). It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. It is reactive and toxic at low doses. Acrylonitrile is one of the components of ABS plastic (acrylonitrile butadiene styrene). Structure and basic properties Acrylonitrile is an organic compound with the formula and the structure . It is a colorless, volatile liquid although commercial samples can be yellow due to impurities. It has a pungent odor of garlic or onions. Its molecular structure consists of a vinyl group () linked to a nitrile (). It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. It is reactive and toxic at low doses. Production Acrylonitrile was first synthesized by the French chemist Charle ... [...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] |
Carbon Fiber
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The properties of the final CFRP product can be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orlon
Acrylic fibers are synthetic fibers made from a polymer (polyacrylonitrile) with an average molecular weight of ~100,000, about 1900 monomer units. For a fiber to be called "acrylic" in the US, the polymer must contain at least 85% acrylonitrile monomer. Typical comonomers are vinyl acetate or methyl acrylate. DuPont created the first acrylic fibers in 1941 and trademarked them under the name Orlon. It was first developed in the mid-1940s but was not produced in large quantities until the 1950s. Strong and warm, acrylic fiber is often used for sweaters and tracksuits and as linings for boots and gloves, as well as in furnishing fabrics and carpets. It is manufactured as a filament, then cut into short staple lengths similar to wool hairs, and spun into yarn. Modacrylic is a modified acrylic fiber that contains at least 35% and at most 85% acrylonitrile. Vinylidene chloride or vinyl bromide used in modacrylic give the fiber flame retardant properties. End-uses of modacrylic in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Ammonium
In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure , where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule. Quats are used in consumer applications including as antimicrobials (such as detergents and disinfectants), fabric softeners, and hair conditioners. As an antimicrobial, they are able to inactivate enveloped viruses (such as SARS-CoV-2). Quats tend to be gentler on surfaces than bleach-based disinfectants, and are generally fabric-safe. Synthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Temperature
Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid. Substances in the molten state generally have reduced viscosity as the temperature increases. An exception to this principle is elemental sulfur, whose viscosity increases in the range of 130 °C to 190 °C due to polymerization. Some organic compounds melt through mesophases, states of partial order between solid and liquid. First order phase transition From a thermodynamics point of view, at the melting point the change in Gibbs free energy ''∆G'' of the substances is zero, but there are non-zero changes in the enthalpy ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Transition Temperature
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. ISO 11357-2: Plastics – Differential scanning calorimetry – Part 2: Determination of glass transition temperature (1999). An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification. The glass-transition temperature ''T''g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, ''T''m, of the crystalline state of the material, if one exists, because the glass is a higher energy state (or enthalpy at const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylformamide
Dimethylformamide, DMF is an organic compound with the chemical formula . Its structure is . Commonly abbreviated as DMF (although this initialism is sometimes used for 2,5-dimethylfuran, dimethylfuran, or dimethyl fumarate), this colourless liquid is Miscibility, miscible with Water (molecule), water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but chemical purity, technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by Sparging (chemistry), sparging samples with an inert gas such as argon or by sonication, sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide, having two methyl groups in the place of the two hydrogens. DMF is a polar molecule, polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leuna Works
The Leuna works () in Leuna, Saxony-Anhalt, is one of the biggest chemical industrial complexes in Germany. The site, now owned jointly by companies such as TotalEnergies, BASF, Linde plc, and DOMO Group, covers 13 km2 and produces a very wide range of chemicals and plastics. Origins Ammonia is an important intermediate product for the manufacture of nitric acid and other nitrogen compounds, needed to produce fertilizers and explosives in particular. The increasing demand for explosives during World War I exceeded the ammonia production capacities of the Oppau works of BASF, who owned the patents for the Haber process. Leuna in central Germany, out of range of French aircraft, was selected as the location of a second plant named ''Badische Anilin- und Sodafabrik, Ammoniakwerk Merseburg''. Construction started on 25 May 1916, and the first tank car with ammonia left the works in April 1917. In 1920, the ammonia works of Leuna and Oppau merged into ''Ammoniakwerke Merseburg- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buna Werke Schkopau
Buna Werke Schkopau were a chemical company specialising in the production of polymer materials such as plastics and artificial rubber. The name BUNA is derived from the technology of polymerising butadiene with sodium (chemical symbol: Na) as a catalyst. History In order to make Germany independent from the importation of natural rubber, the first industrial plant for the production of artificial rubber was built in Schkopau near Halle (Saale) and named ''Buna-Werke GmbH Schkopau''. It was a subsidiary of ''Ammoniakwerk Merseburg GmbH'', later known as '' Leunawerke'', which belonged to IG Farben. The foundation stone was laid in April 1936. Production of artificial rubber started in 1937. Other products were PVC and basic chemicals such as trichlorethylene, formaldehyde, tetrahydrofuran, acetic acid, and acetone. Another factory, ''Hüls-Werke'' in Marl started production of Buna rubber in 1939. World War II During World War II, a branch of Buna-Werke was built near Ausc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ORWO
ORWO (for ''ORiginal WOlfen'') is a registered trademark of the company ORWO Net GmbH, based in Wolfen, Germany, Wolfen and is also traditionally known for black and white film products, made in Germany and sold under the ORWO brand. ORWO was established in East Germany in 1964 as a brand for photographic film and magnetic tape, mainly produced at the former ''ORWO Filmfabrik Wolfen'' (now CChemiepark Bitterfeld-Wolfen, Chemical Park Bitterfeld-Wolfen). The Wolfen factory was founded by Agfa-Gevaert, AGFA (Aktien-Gesellschaft für Anilin-Fabrikation) in 1910, and in 1936 developed Agfacolor, Agfacolor Neu, the first modern colour film which incorporated dye couplers. The division of Germany after World War II saw AGFA divided, into ''Agfa AG, Leverkusen'' in West Germany, and ''VEB Film und Chemiefaserwerk Agfa Wolfen'' in East Germany, which eventually rebranded as ORWO. The company was privatised in 1990 as ORWO AG, but film production ceased at Wolfen in 1994 following the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
