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Polysulfone
Polysulfones are a family of high performance thermoplastics. These polymers are known for their toughness and stability at high temperatures. Technically used polysulfones contain an aryl- SO2-aryl subunit. Due to the high cost of raw materials and processing, polysulfones are used in specialty applications and often are a superior replacement for polycarbonates. Three polysulfones are used industrially: polysulfone (PSU), polyethersulfone (PES/PESU) and polyphenylene sulfone (PPSU). They can be used in the temperature range from -100 to +200 °C and are used for electrical equipment, in vehicle construction and medical technology. They are composed of para-linked aromatics, sulfonyl groups and ether groups and partly also alkyl groups. Polysulfones have outstanding resistance to heat and oxidation, hydrolysis resistance to aqueous and alkaline media and good electrical properties. Nomenclature The term "polysulfone" is normally used for polyarylethersulfones (PAES), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-performance Plastics
High-performance plastics are plastics that meet higher requirements than ''standard'' (Commodity plastics, commodity) or ''Engineering plastic, engineering'' plastics. They are more expensive and used in smaller amounts. Definition High performance plastics differ from standard plastics and engineering plastics primarily by their Thermostability, temperature stability, but also by their chemical resistance and mechanical properties, production quantity, and price. There are many synonyms for the term high-performance plastics, such as: high temperature plastics, high-performance polymers, high performance thermoplastics or high-tech plastics. The name high temperature plastics is in use due to their continuous service temperature (CST), which is always higher than 150 °C by definition (although this is not their only feature, as it can be seen above). The term "polymers" is often used instead of "plastics" because both terms are used as synonyms in the field of engineer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4,4'-Dichlorodiphenyl Sulfone
4,4′-Dichlorodiphenyl sulfone (DCDPS) is an organic compound with the formula (ClC6H4)2SO2. Classified as a sulfone, this white solid is most commonly used as a precursor to polymers that are rigid and temperature-resistant such as PES and Udel. Synthesis and reactions DCDPS is synthesized via sulfonation of chlorobenzene with sulfuric acid, often in the presence of various additives to optimize the formation of the 4,4′-isomer: :ClC6H5 + SO3 → (ClC6H4)2SO2 + H2O It can also be produced by chlorination of diphenylsulfone. With chloride substituents susceptible to substitution, DCDPS is useful in the production of polysulfones. One such polymer, victrex, is prepared by the reaction of DCDPS with 4,4′-sulfonylbisphenol ( bisphenol S). Similarly DCDPS reacts with bisphenol-A Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is Solubility, soluble in most common organic solvents, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azeotropic Distillation
In chemistry, azeotropic distillation is any of a range of techniques used to break an azeotrope in distillation. In chemical engineering, ''azeotropic distillation'' usually refers to the specific technique of adding another component to generate a new, lower-boiling azeotrope that is heterogeneous (e.g. producing two, immiscible liquid phases), such as the example below with the addition of benzene to water and ethanol. This practice of adding an entrainer which forms a separate phase is a specific sub-set of (industrial) Azeotrope#Azeotropy in fluid separation processes, azeotropic distillation methods, or combination thereof. In some senses, adding an entrainer is similar to extractive distillation. Material separation agent The addition of a material separation agent, such as benzene to an ethanol/water mixture, changes the molecular interactions and eliminates the azeotrope. Added in the liquid phase, the new component can alter the activity coefficient of various comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly corrosive base (chemistry), base and alkali that decomposes lipids and proteins at ambient temperatures and at high concentrations may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates . The monohydrate crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide" is often this monohydrate, and published data may refer to it instead of the anhydrous compound. As one of the simplest hydroxides, sodium hydroxide is frequently used alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students. Sodium hydroxide is used in many industries: in the making of wood pulp and paper, tex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenoxide
Phenolates (also called phenoxides) are anions, salts, and esters of phenols, containing the phenolate ion. They may be formed by reaction of phenols with strong base. Properties Alkali metal phenolates, such as sodium phenolate hydrolyze in aqueous solution to form basic solutions. At pH = 10, phenol and phenolate are in approximately 1:1 proportions. The phenoxide anion (aka phenolate) is a strong nucleophile with a comparable to the one of carbanions or tertiary amines. Generally, oxygen attack of phenoxide anions is kinetically favored, while carbon-attack is thermodynamically preferred (see Thermodynamic versus kinetic reaction control). Mixed oxygen/carbon attack and by this a loss of selectivity is usually observed if the reaction rate reaches diffusion control. Uses Alkyl aryl ethers can be synthesized through the Williamson ether synthesis by treating sodium phenolate with an alkyl halide: :C6H5ONa + CH3I → C6H5OCH3 + NaI :C6H5ONa + (CH3O)2SO2 → C6H5OCH3 + (CH3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycondensation
In polymer chemistry, condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction (i.e. a small molecule, such as water or methanol, is produced as a byproduct). Natural proteins as well as some common plastics such as nylon and PETE are formed in this way. Condensation polymers are formed by polycondensation, when the polymer is formed by condensation reactions between species of all degrees of polymerization, or by condensative chain polymerization, when the polymer is formed by sequential addition of monomers to an active site in a chain reaction. The main alternative forms of polymerization are chain polymerization and polyaddition, both of which give addition polymers. Condensation polymerization is a form of step-growth polymerization. Linear polymers are produced from bifunctional monomers, i.e. compounds with two reactive end-groups. Common condensation polymers include polyesters, polyamides such as nylon, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthesis Polysulfone Possibility 2 Part 2
Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organic compounds ***Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes ***Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses **Dehydration synthesis, a chemical synthesis resulting in the loss of a water molecule *Biosynthesis, the creation of an organic compound in a living organism, usually aided by enzymes **Photosynthesis, a biochemical reaction using a carbon molecule to produce an organic molecule, using sunlight as a catalyst **Chemosynthesis, the synthesis of biological compounds into organic waste, using methane or an oxidized molecule as a catalyst **Amino acid synthesis, the synthesis of an amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimony Pentachloride
Antimony pentachloride is a chemical compound with the formula SbCl5. It is a colourless oil, but typical samples are yellowish due to dissolved chlorine. Owing to its tendency to hydrolyse to hydrochloric acid, SbCl5 is a highly corrosive substance and must be stored in glass or PTFE containers. Preparation and structure Antimony pentachloride is prepared by passing chlorine gas into molten antimony trichloride: :SbCl3 + Cl2 → SbCl5 Gaseous SbCl5 has a trigonal bipyramidal structure. Reactions This compounds reacts with water to form antimony pentoxide and hydrochloric acid: :2 SbCl5 + 5 H2O → Sb2O5 + 10 HCl The mono- and tetrahydrates are known, SbCl5·H2O and SbCl5·4H2O. This compound forms adducts with many Lewis bases. SbCl5 is a soft Lewis acid and its ECW model parameters are EA = 3.64 and CA = 10.42. It is used as the standard Lewis acid in the Gutmann scale of Lewis basicity. It is also a strong oxidizing agent. For example aromatic ethers are oxidize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferric Chloride
Iron(III) chloride describes the inorganic compounds with the formula (H2O)x. Also called ferric chloride, these compounds are some of the most important and commonplace compounds of iron. They are available both in anhydrous and in hydrated forms, which are both hygroscopic. They feature iron in its +3 oxidation state. The anhydrous derivative is a Lewis acid, while all forms are mild oxidizing agents. It is used as a water treatment, water cleaner and as an Chemical milling, etchant for metals. Electronic and optical properties All forms of ferric chloride are paramagnetic, owing to the presence of unpaired electrons residing in 3d orbitals. Although Fe(III) chloride can be octahedral or tetrahedral (or both, see structure section), all of these forms have five unpaired electrons, one per d-orbital. The spin states (d electrons), high spin d5 electronic configuration requires that d-d electronic transitions are spin forbidden, in addition to violating the Laporte rule. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
