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Fluorotelomer Ethoxylate
Fluorotelomers are fluorocarbon-based oligomers, or telomers, synthesized by telomerization. Some fluorotelomers and fluorotelomer-based compounds are a source of environmentally persistent perfluorinated carboxylic acids such as PFOA and PFNA, while others are under extended investigation. Types There are many broad categories of fluorotelomers: * Fluorotelomer alcohols (FTOH) * Fluorotelomer ethoxylates (FTEO) * Fluorotelomer fumarates * Fluorotelomer methacrylates (FTMAC) * Fluorotelomer sulphonates (FTS) Manufacture In the radical telomerization of fluorotelomer molecules, a variety of fluorinated alkenes can serve as unsaturated taxogens including tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, and hexafluoropropene. However, many fluorotelomers, such as fluorotelomer alcohols, are fluorocarbon-based because they are synthesized from tetrafluoroethylene. In addition to alcohols, synthetic products include fluorotelomer iodides, olefins, and acrylate mo ... [...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 has distinctive properties, e.g., enhanced stability, volatility, and hydrophobicity. Fluorocarbons and their derivatives are commercial polymers, refrigerants, drugs, and anesthetics. Nomenclature Perfluorocarbons or PFCs, are organofluorine compounds with the formula CxFy, i.e., they contain only carbon and fluorine. The terminology is not strictly followed and many fluorine-containing organic compounds are 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 Compounds with the prefix perfluoro- are hydrocarbons, including those with heteroatoms, wherein all C-H bonds have been replaced by C-F bonds.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 strength is a resu ... [...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. The thermal dimerization of chlorotrifluoroethylene gives 1,2-dichloro-1,2,3,3,4,4-hexafluorocyclobutane. Dichlorination of the latter gives hexafluorocyclobutene Hexafluorocyclobutene is the organofluorine compound with the formula (CF2)2(CF)2. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on December 2, 1970, after Nixon signed an executive order. The order establishing the EPA was ratified by committee hearings in the House and Senate. The agency is led by its administrator, who is appointed by the president and approved by the Senate. The current administrator is Michael S. Regan. The EPA is not a Cabinet department, but the administrator is normally given cabinet rank. The EPA has its headquarters in Washington, D.C., regional offices for each of the agency's ten regions and 27 laboratories. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state, tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telomerization
Telomerization is a reaction that produces a particular kind of oligomer with two distinct end groups. The oligomer is called a telomer. Some telomerizations proceed by radical pathways, many do not. A generic equation is: : A-B + n M -> A-M_-B where M is the monomer, and A and B are the end groups, and n is the degree of polymerization. One example is the coupled dimerization and hydroesterification of 1,3-butadiene. This step produces a doubly unsaturated C9-ester: :2CH2=CH-CH=CH2 + CO + CH3OH → CH2=CH(CH2)3CH=CHCH2CO2CH3 The monomer in this reaction is butadiene, the degree of polymerization is 2, and the end groups are vinyl and the carboxy methyl (CO2CH3). This and several related reactions proceed with palladium catalysts. Many telomerizations are used in industrial chemistry. Nomenclature According to the jargon in polymer chemistry, telomerization requires a telogen to react with at least one unsaturated taxogen molecule. Fluorotelomers are an example. See also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burger King
Burger King (BK) is an American-based multinational chain store, chain of hamburger fast food restaurants. Headquartered in Miami-Dade County, Florida, the company was founded in 1953 as Insta-Burger King, a Jacksonville, Florida–based restaurant chain. After Insta-Burger King ran into financial difficulties in 1954, its two Miami-based franchisees David Edgerton (1927–2018) and James McLamore (1926–1996) purchased the company and renamed it "Burger King". Over the next half-century, the company changed hands four times and its third set of owners, a partnership of TPG Capital, Bain Capital, and Goldman Sachs Capital Partners took it public in 2002. In late 2010, 3G Capital of Brazil acquired a majority stake in the company, in a deal valued at US$3.26 billion. The new owners promptly initiated a restructuring of the company to reverse its fortunes. 3G, along with partner Berkshire Hathaway, eventually merged the company with the Canadian-based doughnut chain Tim Hortons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popcorn Bag
Microwave popcorn is a convenience food consisting of unpopped popcorn in an enhanced, sealed paper bag intended to be heated in a microwave oven. In addition to the dried corn, the bags typically contain cooking oil with sufficient saturated fat to solidify at room temperature, one or more seasonings (often salt), and natural or artificial flavorings or both. With the many different flavors, there are many different providers. Design The bag is typically partially folded when it is placed in a microwave, and inflates as a result of steam pressure from the heated kernels. Microwave popcorn bags are designed to avoid popped-kernel scorching, an undesirable effect that takes place when popped kernels are heated above . A susceptor—usually a metalized film laminated onto the paper of the bag—absorbs microwaves and concentrates heat at the film interface, thus ensuring a heat distribution focused on the hard-to-heat flavor coating so that the unpopped kernels are evenly coate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parts Per Billion
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, ), parts-per-billion (ppb, ), parts-per-trillion (ppt, ) and parts-per-quadrillion (ppq, ). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous. Overview Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it is common to assume that the density of water is 1.00 g/mL. Therefore, it is common to equate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolized
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic'' – the ''breaking down'' of compounds (for example, of glucose to pyruvate by cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipophobicity
Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means "fat rejection", literally "fear of fat". Lipophobic compounds are those not soluble in lipids or other non-polar solvents. From the other point of view, they do not absorb fats. "Oleophobic" (from the Latin ''oleum'' "oil", Greek ελαιοφοβικό ''eleophobico'' from έλαιο ''eleo'' "oil" and φόβος ''phobos'' "fear") refers to the physical property of a molecule that is seemingly repelled from oil. (Strictly speaking, there is no repulsive force involved; it is an absence of attraction.) The most common lipophobic substance is water. Fluorocarbons are also lipophobic/oleophobic in addition to being hydrophobic. Uses A lipophobic coating has been used on the touchscreens of Apple's iPhones since the 3GS, their iPads, Nokia's N9 and Lumia devices, the HTC HD2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. 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 compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Monomers can be classified in many ways. They can be subdivided into two broad classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: : Other classifications include: *natural vs synthetic monomers, e.g. glycine vs caprolactam, respectively *polar vs nonpolar monomers, e.g. vinyl acetate vs ethylene, respectively *cyclic vs linear, e.g. ethylene oxide vs ethylene glycol, respectively The polymerization of one kind of monomer gives a homopolymer. Many polymers are copolymers, meaning that they are derived from two different monomers. In the case of condensation polymerizations, the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrylate
Acrylates (IUPAC: prop-2-enoates) are the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion C H2=CHC OO−. Often, acrylate refers to esters of acrylic acid, the most common member being methyl acrylate. These acrylates contain vinyl groups. These compounds are of interest because they are bifunctional: the vinyl group is susceptible to polymerization and the carboxylate group carries myriad functionalities. Modified acrylates are also numerous, some examples being methacrylates (CH2=C(CH3)CO2R) and cyanoacrylates (CH2=C(CN)CO2R). Acrylate can also refer to polyacrylates prepared through the polymerization of the vinyl groups of acrylate monomers. File:Acrylate-anion.svg, The acrylate anion File:Trimethylolpropane triacrylate.svg, Trimethylolpropane triacrylate (TMPTA), a trifunctional acrylate ester File:Methylacrylat.svg, Methyl acrylate, an acrylic ester File:Hexandioldiacrylat.svg, Hexandiol diacrylate, a bifunctional acrylate File:Methyl-meth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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