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Azodicarbonamide
Azodicarbonamide, ADCA, ADA, or azo(''bis'')formamide, is a chemical compound with the molecular formula C2H4O2N4. It is a yellow to orange-red, odorless, crystalline powder. It is sometimes called a 'yoga mat' chemical because of its widespread use in foamed plastics. It was first described by John Bryden in 1959. Synthesis It is prepared in two steps via treatment of urea with hydrazine to form biurea, as described in this idealized equation: :2 OC(NH2)2 + N2H4 → H2NC(O)-N(H)-N(H)-C(O)NH2 + 2 NH3 Oxidation with chlorine or chromic acid yields azodicarbonamide: :H2NC(O)-N(H)-N(H)-C(O)NH2 + Cl2 → H2NC(O)-N=N-C(O)NH2 + 2 HCl Applications Blowing agent The principal use of azodicarbonamide is in the production of foamed plastics as a blowing agent. The thermal decomposition of azodicarbonamide produces nitrogen, carbon monoxide, carbon dioxide, and ammonia gases, which are trapped in the polymer as bubbles to form a foamed article. Azodicarbonamide is used in plastics, syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biurea
Biurea is a chemical compound with the molecular formula C2H6N4O2. It is produced in food products containing azodicarbonamide, a common ingredient in bread flour, when they are cooked. Upon exposure, biurea is rapidly eliminated from the body through excretion. Biurea is produced from urea and hydrazine by transamidation. Its major use is as a chemical intermediate in the production of azodicarbonamide, a common blowing agent. References {{reflist External links Biurea NLM Hazardous Substances Data Bank The Hazardous Substances Data Bank (HSDB) is a toxicology database on the United States, U.S. National Library of Medicine's (NLM) Toxicology Data Network (TOXNET). It focuses on the toxicology of potentially hazardous chemicals, and includes inf ... Semicarbazides Ureas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subway (restaurant)
Subway is an American multinational fast food restaurant franchise that specializes in submarine sandwiches (subs), wraps, salads and drinks. Subway was founded by 17-year-old Fred DeLuca and financed by Peter Buck in 1965 as Pete's Super Submarines in Bridgeport, Connecticut. After several name changes in the beginning years, it was finally renamed Subway in 1972, and a franchise operation began in 1974 with a second restaurant in Wallingford, Connecticut. Since then, it has expanded to become a global franchise. Subway serves an array of topping choices, allowing the customer to choose which toppings are included in their sandwich. The longtime Subway slogan, "Eat Fresh", is intended to indicate the fresh ingredients that are used in their sandwiches. It was the fastest-growing franchise in the world in 2015 and, as of June 2021, had 37,540 locations in more than 100 countries and territories. More than half its locations (21,796 or 58.1%) are in the United States. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dough Conditioner
A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to bread dough to strengthen its texture or otherwise improve it in some way. Dough conditioners may include enzymes, yeast nutrients, mineral salts, oxidants and reductants, bleaching agents and emulsifiers. They are food additives combined with flour to improve baking functionality. Flour treatment agents are used to increase the speed of dough rising and to improve the strength and workability of the dough. While they are an important component of modern factory baking, some small-scale bakers reject them in favour of longer fermentation periods that produce greater depth of flavour. These agents are often sold as mixtures in a soy flour base, as only small amounts are required. Examples Examples of dough conditioners include ascorbic acid, distilled monoglycerides, citrate ester of monoglycerides, diglycerides, ammonium chloride, enzymes, diacetyl tartaric acid e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blowing Agent
A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied when the blown material is in a liquid stage. The cellular structure in a matrix reduces density, increasing thermal and acoustic insulation, while increasing relative stiffness of the original polymer. Blowing agents (also known as 'pneumatogens') or related mechanisms to create holes in a matrix producing cellular materials, have been classified as follows: *Physical blowing agents include CFCs (however, these are ozone depletants, banned by the Montreal Protocol of 1987), HCFCs (replaced CFCs, but are still ozone depletants, therefore being phased out), hydrocarbons (e.g. pentane, isopentane, cyclopentane), and liquid CO2. The bubble/foam-making process is irreversible and endothermic, i.e. it needs heat (e.g. from a melt process or the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicarbazide
Semicarbazide is the chemical compound with the formula OC(NH2)(N2H3). It is a water-soluble white solid. It is a derivative of urea. Synthesis The compound prepared by treating urea with hydrazine:Jean-Pierre Schirmann, Paul Bourdauducq "Hydrazine" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. . :OC(NH2)2 + N2H4 → OC(NH2)(N2H3) + NH3 A further reaction can occur to give carbohydrazide: :OC(NH2)(N2H3) + N2H4 → OC(N2H3)2 + NH3 Derivatives Semicarbazide is frequently reacted with aldehydes and ketones to produce semicarbazones via a condensation reaction. This is an example of imine formation resulting from the reaction of a primary amine with a carbonyl group. The reaction is useful because semicarbazones, like oximes and 2,4-DNPs, typically have high melting points and crystallize, facilitating purification or identification of reaction products. Properties Semicarbazide products (semicarbazones and thiosemicarbazones) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing polymer foams, but applications also include its uses as a precursor to polymerization catalysts, pharmaceuticals, and agrochemicals, as well as a long-term storable propellant for in-space spacecraft propulsion. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. the world hydrazine hydrate market amounted to $350 million. About two million tons of hydrazine hydrate were used in foam blowing agents in 2015. Hydrazines r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Electronegativity#Pauling electronegativity, Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval Alchemy, alchemists, which commonly involved the heating of chloride Salt (chemistry), salts like ammonium chloride (sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and hydrochloric acid (in the form of ). However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is , with an estimated 2020 population of more than 67 million people. The United Kingdom has evolved from a series of annexations, unions and separations of constituent countries over several hundred years. The Treaty of Union between the Kingdom of England (which included Wales, annexed in 1542) and the Kingdom of Scotland in 170 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Of Federal Regulations
In the law of the United States, the ''Code of Federal Regulations'' (''CFR'') is the codification of the general and permanent regulations promulgated by the executive departments and agencies of the federal government of the United States. The CFR is divided into 50 titles that represent broad areas subject to federal regulation. The CFR annual edition is published as a special issue of the '' Federal Register'' by the Office of the Federal Register (part of the National Archives and Records Administration) and the Government Publishing Office. In addition to this annual edition, the CFR is published online on the Electronic CFR (eCFR) website, which is updated daily. Background Congress frequently delegates authority to an executive branch agency to issue regulations to govern some sphere. These statutes are called "enabling legislation." Enabling legislation typically has two parts: a substantive scope (typically using language such as "The Secretary shall promulgate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parts Per Million
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 equat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Official Journal Of The European Union
An official is someone who holds an office (function or mandate, regardless whether it carries an actual working space with it) in an organization or government and participates in the exercise of authority, (either their own or that of their superior and/or employer, public or legally private). An elected official is a person who is an official by virtue of an election. Officials may also be appointed ''ex officio'' (by virtue of another office, often in a specified capacity, such as presiding, advisory, secretary). Some official positions may be Inheritance, inherited. A person who currently holds an office is referred to as an incumbent. Something "official" refers to something endowed with governmental or other authoritative recognition or mandate, as in official language, official gazette, or official scorer. Etymology The word ''official'' as a noun has been recorded since the Middle English period, first seen in 1314. It comes from the Old French ''official'' (12th centur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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