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Ammonium Polyphosphate
Ammonium polyphosphate is an inorganic salt of polyphosphoric acid and ammonia containing both chains and possibly branching. Its chemical formula is H4 PO3sub>n(OH)2 showing that each monomer consists of an orthophosphate radical of a phosphorus atom with three oxygens and one negative charge neutralized by an ammonium cation leaving two bonds free to polymerize. In the branched cases some monomers are missing the ammonium anion and instead link to three other monomers. The properties of ammonium polyphosphate depend on the number of monomers in each molecule and to a degree on how often it branches. Shorter chains (n1000), but short polymer chains (''e.g.'' pyro-, tripoly-, and tetrapoly-) are more soluble and show increasing solubility with increasing chain length. Ammonium polyphosphate can be prepared by reacting concentrated phosphoric acid with ammonia. However, iron and aluminum impurities, soluble in concentrated phosphoric acid, form gelatinous precipitates or "slu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphosphoric Acid
A phosphoric acid, in the general sense, is a phosphorus oxoacid in which each phosphorus (P) atom is in the oxidation state +5, and is bonded to four oxygen (O) atoms, one of them through a double bond, arranged as the corners of a tetrahedron. Two or more of these tetrahedra may be connected by shared single-bonded oxygens, forming linear or branched chains, cycles, or more complex structures. The single-bonded oxygen atoms that are not shared are completed with acidic hydrogen atoms. The general formula of a phosphoric acid is , where ''n'' is the number of phosphorus atoms and ''x'' is the number of fundamental cycles in the molecule's structure, between 0 and (''n''+2)/2. Removal of protons () from ''k'' hydroxyl groups –OH leaves anions generically called phosphates (if ''k'' = ''n''−2''x''+2) or hydrogen phosphates (if ''k'' is between 1 and ''n''−2''x''+1), with general formula ''n''−2''x''+2−''k''P''n''O3''n''+1−''x''sup>''k''−. The fully dissociated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flame Retardant
The term flame retardants subsumes a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and are intended to prevent or slow the further development of ignition by a variety of different physical and chemical methods. They may be added as a copolymer during the polymerisation process, or later added to the polymer at a moulding or extrusion process or (particularly for textiles) applied as a topical finish. Mineral flame retardants are typically additive while organohalogen and organophosphorus compounds can be either reactive or additive. Classes Both Reactive and Additive Flame retardants types, can be further separated into four distinct classes: * Minerals such as aluminium hydroxide (ATH), magnesium hydroxide (MDH), huntite and hydromagnesite, various hydrates, red phosphorus, and boron compounds, mostly borates. * Organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Compounds
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (), where one or more hydrogen atoms are replaced by organic groups (indicated by R). Acid–base properties The ammonium ion is generated when ammonia, a weak base, reacts with Brønsted acids (proton donors): :H+ + NH3 -> H4 The ammonium ion is mildly acidic, reacting with Brønsted bases to return to the uncharged ammonia molecule: : H4 + B- -> HB + NH3 Thus, treatment of concentrated solutions of ammonium salts with strong base gives ammonia. When ammonia is dissolved in water, a tiny amount of it converts to ammonium ions: :H2O + NH3 OH- + H4 The degree to which ammonia forms the ammonium ion depends on the pH of the solution. If the pH is low, the equilibrium shifts to the right: more ammonia molecules are conv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymers
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'', meani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Additives
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (salting), smoke (smoking), sugar (crystallization), etc. This allows for longer-lasting foods such as bacon, sweets or wines. With the advent of processed foods in the second half of the twentieth century, many additives have been introduced, of both natural and artificial origin. Food additives also include substances that may be introduced to food indirectly (called "indirect additives") in the manufacturing process, through packaging, or during storage or transport. Numbering To regulate these additives and inform consumers, each additive is assigned a unique number called an "E number", which is used in Europe for all approved additives. This numbering scheme has now been adopted and extended by the '' Codex Alimentarius'' Commission t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Farm Service
Agrium was a major retail supplier of agricultural products and services in North America, South America and Australia and a wholesale producer and marketer of all three major agricultural nutrients and a supplier of specialty fertilizers in North America. In 2018, Agrium merged with PotashCorp to form Nutrien. History Agrium was founded as Cominco Fertilizers (short for Consolidated Mining and Smelting Company) in 1931 and changed its name to Agrium in 1995. Agrium was headquartered in Calgary, Alberta, Canada. Crop Production Services, Inc., a subsidiary company, was based in Loveland, Colorado and was the location of Agrium's Retail Business Unit head office. The company was a part-owner of Canpotex, which manages all potash exporting from Saskatchewan. On September 12, 2016, Agrium announced that it had agreed to merge with PotashCorp, which will make the combined company, Nutrien, the largest producer of potash and second-largest producer of nitrogen fertilizer worldwi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennessee Valley Authority
The Tennessee Valley Authority (TVA) is a federally owned electric utility corporation in the United States. TVA's service area covers all of Tennessee, portions of Alabama, Mississippi, and Kentucky, and small areas of Georgia, North Carolina, and Virginia. While owned by the federal government, TVA receives no taxpayer funding and operates similarly to a private for-profit company. It is headquartered in Knoxville, Tennessee, and is the sixth largest power supplier and largest public utility in the country. The TVA was created by Congress in 1933 as part of President Franklin D. Roosevelt's New Deal. Its initial purpose was to provide navigation, flood control, electricity generation, fertilizer manufacturing, regional planning, and economic development to the Tennessee Valley, a region that had suffered from lack of infrastructure and poverty during the Great Depression, relative to the rest of the nation. TVA was envisioned both as a power supplier and a regional economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intumescent
An intumescent is a substance that swells as a result of heat exposure, leading to an increase in volume and decrease in density. Intumescent materials are typically used in passive fire protection and require listing, approval, and compliance in their installed configurations in order to comply with the national building codes and laws. The details for individual building parts are specified in technical standards which are compiled and published by national or international standardization bodies like the British Standards Institute (BSI), the German Institute for Standardization (DIN), the American Society for Testing and Materials (ASTM) or the International Standardization Organization (ISO). Intumescent coatings for steel constructions must be approved in standardized fire tests. Types Soft char These intumescent materials produce a light char which is a poor conductor of heat, thus retarding heat transfer. Typically the light char consist of microporous carbonaceous foam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoechst AG
Hoechst AG () was a German chemicals then 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 Hoechst facilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyurethane
Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from a wide range of starting materials. This chemical variety produces polyurethanes with different chemical structures leading to many List of polyurethane applications, different applications. These include rigid and flexible foams, varnishes and coatings, adhesives, Potting (electronics), electrical potting compounds, and fibers such as spandex and Polyurethane laminate, PUL. Foams are the largest application accounting for 67% of all polyurethane produced in 2016. A polyurethane is typically produced by reacting an isocyanate with a polyol. Since a polyurethane contains two types of monomers, which polymerize one after the other, they are classed as Copolymer#Alternating copolymers, alternating copolymers. Both the isocy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyolefin
A polyolefin is a type of polymer with the general formula (CH2CHR)n where R is an alkyl group. They are usually derived from a small set of simple olefins (alkenes). Dominant in a commercial sense are polyethylene and polypropylene. More specialized polyolefins include polyisobutylene and polymethylpentene. They are all colorless or white oils or solids. Many copolymers are known, such as polybutene, which derives from a mixture of different butene isomers. The name of each polyolefin indicates the olefin from which it is prepared; for example, polyethylene is derived from ethylene, and polymethylpentene is derived from 4-methyl-1-pentene. Polyolefins are not olefins themselves because the double bond of each olefin monomer is opened in order to form the polymer. Monomers having more than one double bond such as butadiene and isoprene yield polymers that contain double bonds ( polybutadiene and polyisoprene) and are usually not considered polyolefins. Polyolefins are the foundat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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