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Fluoropolymers
A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and Base (chemistry), bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon," trademarked by the DuPont, DuPont Company. History In 1938, polytetrafluoroethylene (DuPont brand name Teflon) was discovered by accident by a recently hired DuPont Ph.D., Roy J. Plunkett. While working with tetrafluoroethylene gas to develop refrigerants, he noticed that a previously pressurized cylinder had no pressure remaining. In dissecting the cylinder, he found a mass of white solid in a quantity similar to that of the tetrafluoroethylene gas. It was determined that this material was a new-to-the-world polymer. Tests showed the substance was resistant to corrosion from most acids, bases and solvents and had better high temperature stability than any other plastic. By early 1941, a crash program was making substa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytetrafluoroethylene
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a corporate spin-off, spin-off from DuPont (1802–2017), DuPont, which originally invented the compound in 1938. Polytetrafluoroethylene is a fluorocarbon solid, as it is a high-molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances Wetting, wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low polarizability, electric polarizability of fluorine. PTFE has one of the lowest Friction#Coefficient of friction, coefficients of friction of any solid. Polytetrafluoroethylene is used as a non-stick coating for Cookware and bakeware, pans and other Cookware and bakeware, cookware. It is Chemically inert, non-reactive, partly because of the strength of car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyvinyl Fluoride
Polyvinyl fluoride (PVF) or –(CH2CHF)n– is a polymer material mainly used in the flammability-lowering coatings of airplane interiors and photovoltaic module backsheets. It is also used in raincoats and metal sheeting. Polyvinyl fluoride is a thermoplastic fluoropolymer with a repeating vinyl fluoride unit, and it is structurally very similar to polyvinyl chloride. History The PVF-based film was first commercialised in 1961 by DuPont under the name Tedlar. Polymerization The most widely used polymerizations of VF are in aqueous suspensions or emulsions. High pressures are required because of the VF volatility. The high electronegativity of fluorine makes the polymerization more difficult when compared to other vinyl halides. The polymerization temperatures range from 50 °C to 150 °C and can affect the crystallinity, melting point and branching of the product. Initiation is done by peroxides or azo compounds. The resonance stabilization of the propagating intermed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorocycloalkene
A perfluorocycloalkene (PFCA) fluorocarbon structure with a cycloalkene core. PFCAs have shown reactivity with a wide variety of nucleophiles including phenoxides, alkoxides, organometallic, amines, thiols, and azoles. They or their derivatives are reported to have nonlinear optical activity, and be useful as lubricants, etching agents, components of fuel cells, low-dielectric materials, and superhydrophobic coating, superhydrophobic and oleophobic coatings. File:Tetrafluorocyclopropene.png, Tetrafluorocyclopropene File:Hexafluorocyclobutene.png, Hexafluorocyclobutene File:Octafluorocyclopentene.png, Octafluorocyclopentene File:Decafluorocyclohexene.png, Decafluorocyclohexene Reactivity Derivatization of these PFCA rings via displacement of fluorine atoms with nucleophiles occurs through an addition-elimination reaction in the presence of a base. Attack of the nucleophile on the PFCA ring generates a carbanion which can eliminate a fluoride ion, resulting in vinyl substituted an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PVDF
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. Its chemical formula is (C2H2F2)''n''. PVDF is a specialty plastic used in applications requiring the highest purity, as well as resistance to solvents, acids and hydrocarbons. PVDF has low density 1.78 g/cm3 in comparison to other fluoropolymers, like polytetrafluoroethylene. It is available in the form of piping products, sheet, tubing, films, plate and an insulator for premium wire. It can be injected, molded or welded and is commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium-ion batteries. It is also available as a cross-linked closed-cell foam, used increasingly in aviation and aerospace applications, and as an exotic 3D printer filament. It can also be used in repeated contact with food products, as it is FDA-compliant and non-toxic below its degr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluoroether
Perfluoroethers are a class of organofluorine compound containing one or more ether functional group. In general these compounds are structurally analogous to the related hydrocarbon ethers, except for the distinctive properties of fluorocarbons. The introduction of an ether function to a perfluoro-polymer chain also provides thermoplastic properties to the polymer, making thermal forming possible. This is a great technological advantage for producing a large variety of shapes (e.g., beakers, funnels, flasks for laboratory uses, etc...) and allows extrusion of highly chemically-resistant tubing. It also confers on the polymer a translucent appearance. Low molecular weight fluorinated ethers Acyclic perfluoroethers are analogues of diethylether, e.g. O(C2F5)2, such perfluoro(2-ethoxyethane)sulfonic acid (PFEESA). Of practical utility are the fluorinated epoxides. Tetrafluoroethylene oxide and hexafluoropropylene oxide. These are precursors of perfluoro(methyl vinyl ether) ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorocarbon
Fluorocarbons are chemical compounds with carbon-fluorine bonds. Compounds that contain many C-F bonds often have distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Several fluorocarbons and their derivatives are commercial polymers, refrigerants, drugs, and anesthetics. Nomenclature Perfluorocarbons or PFCs, are organofluorine compounds with the formula CxFy, meaning they contain only carbon and fluorine. The terminology is not strictly followed and many fluorine-containing organic compounds are also called fluorocarbons. Compounds with the prefix perfluoro- are hydrocarbons, including those with heteroatoms, wherein all C-H bonds have been replaced by C-F bonds. Fluorocarbons includes perfluoroalkanes, fluoroalkenes, fluoroalkynes, and perfluoroaromatic compounds. Perfluoroalkanes Chemical properties Perfluoroalkanes are very stable because of the strength of the carbon–fluorine bond, one of the strongest in organic chemistry. Its st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AGC Inc
AGC may refer to: Organizations In business * AGC Inc. (formerly Asahi Glass Co.), a glass manufacturer * Associated General Contractors of America, an association of commercial construction contractors * Australian Guarantee Corporation, a financial company Military * Army Geospatial Center, part of the US Army Corps of Engineers * Adjutant General's Corps, in the British Army * A retired US Navy hull classification symbol: List of United States Navy amphibious warfare ships#Amphibious force flagship (AGC), Amphibious force flagship (AGC) Religious organizations * Apostolic Generation Church, a non-denominational church located in Jakarta, Indonesia * Associated Gospel Churches of Canada, a Canadian evangelical Christian denomination Other organizations * Assyrian General Conference, a political organization in Iraq * Clan del Golfo , Autodefensas Gaitanistas de Colombia (aka The Gulf Clan), a drug cartel and paramilitary group in Colombia Science and technology * All glass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluoro(methyl Vinyl Ether)
Perfluoro(methyl vinyl ether) is a perfluorinated compound used as a precursor to fluoropolymers. It is the simplest unsaturated perfluoroether. Preparation Preparation begins with hexafluoropropylene oxide (HFPO) and carbonyl fluoride over a metal fluoride catalyst. The fluoride reacts with the carbonyl, forming a perfluoroalkoxide anion. The anion attacks the electrophilic central carbon atom of HFPO in a nucleophilic ring-opening reaction similar to anionic polymerization. Elimination of fluoride regenerates the catalyst and yields perfluoro(2-methoxy propionyl fluoride). The acyl fluoride is then treated with potassium hydroxide to produce the perfluorocarboxylate. The carboxylate is then heated, causing decarboxylation followed by elimination of fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an Inorganic chemistry, inorganic, Monatomic ion, monatomic Ion#Anions and cations, anion of fluorine, with the chemical f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexafluoropropylene
Hexafluoropropylene is the fluoroalkene with the formula CF3CF=CF2. It is the perfluorocarbon counterpart to the hydrocarbon propylene. It is mainly used to produce copolymers with tetrafluoroethylene. Hexafluoropropylene is used as a chemical intermediate. Preparation Hexafluoropropylene can be produced by pyrolysis of tetrafluoroethylene Tetrafluoroethylene (TFE) is a fluorocarbon with the chemical formula . It is a colorless gas. Its structure is . It is used primarily in the industrial preparation of fluoropolymers. It is the simplest perfluorinated alkene. It was first repor ...: :3CF2=CF2 → 2CF3CF=CF2 It can also be prepared from chlorodifluoromethane, or produced from various chlorofluorocarbons. References Perfluoroalkenes {{organohalide-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propylene
Propylene, also known as propene, is an unsaturated organic compound with the chemical formula . It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor. Propylene is a product of combustion from forest fires, cigarette smoke, and motor vehicle and aircraft exhaust. It was discovered in 1850 by A. W. von Hoffmann's student Captain (later Major General) John Williams Reynolds as the only gaseous product of thermal decomposition of amyl alcohol to react with chlorine and bromine. Production Steam cracking The dominant technology for producing propylene is steam cracking, using propane as the feedstock. Cracking propane yields a mixture of ethylene, propylene, methane, hydrogen gas, and other related compounds. The yield of propylene is about 15%. The other principal feedstock is naphtha, especially in the Middle East and Asia. Propylene can be separated by fractional distill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorotrifluoroethylene
Chlorotrifluoroethylene (CTFE) is a chlorofluorocarbon with chemical formula CFCl=CF2. It is commonly used as a refrigerant in cryogenic applications. CTFE has a carbon-carbon double bond and so can be polymerized to form polychlorotrifluoroethylene or copolymerized to produce the plastic ECTFE. PCTFE has the trade name Neoflon PCTFE from Daikin Industries in Japan, and it used to be produced under the trade name Kel-F from 3M Corporation in Minnesota. Production and reactions Chlorotrifluoroethylene is produced commercially by the dechlorination of 1,1,2-trichloro-1,2,2-trifluoroethane with zinc: :CFCl2-CF2Cl + Zn → CClF=CF2 + ZnCl2 In 2012, an estimated 1–10 million pounds were produced commercially in the United States. Addition of iodine monochloride to chlorotrifluoroethylene gives iododichlorotrifluoroethane: : The latter is a precursor to hexafluorobutadiene. Thermal dimerization of chlorotrifluoroethylene gives 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
