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Methacrolein
Methacrolein, or methacrylaldehyde, is an unsaturated aldehyde. It is a clear, colorless, flammable liquid. Methacrolein is one of two major products resulting from the reaction of isoprene with OH in the atmosphere, the other product being methyl vinyl ketone (MVK, also known as butenone). These compounds are important components of the atmospheric oxidation chemistry of biogenic chemicals, which can result in the formation of ozone and/or particulates. Methacrylaldehyde is also present in cigarette smoke. It can be found in the essential oil of the plant Big Sagebrush (''Artemisia tridentata'') which contains 5% methacrolein. Industrially, the primary use of methacrolein is in the manufacture of polymers and synthetic resins. Exposure to methacrolein is highly irritating to the eyes, nose, throat and lungs. See also * Acrolein * Methacrylic acid Methacrylic acid, abbreviated MAA, is an organic compound with the formula CH2=C(CH3)CO2H. This colorless, viscous liquid is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citral
Citral is an acyclic monoterpene aldehyde. Being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans''-citral; α-citral) or citral A. The ''Z''-isomer is named neral (''cis''-citral; β-citral) or citral B. These stereoisomers occur as a mixture, often not in equal proportions; e.g. in essential oil of Australian ginger, the neral to geranial ratio is 0.61. Natural Occurrence Citral is present in the volatile oils of several plants: Further, in the lipid fraction (essential oil) of Australian ginger (51–71%) Of the many sources of citral, the Australian myrtaceous tree, lemon myrtle, '' Backhousia citriodora'' F. Muell. (of the family Myrtaceae), is considered superior. Uses Citral is a precursor in the industrial production of vitamin A, vitamin E, vitamin K. Citral is also precursor to lycopene, ionone and methylionone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citronellal
Citronellal or rhodinal ( C10 H18 O) is a monoterpenoid aldehyde, the main component in the mixture of terpenoid chemical compounds that give citronella oil its distinctive lemon scent. Citronellal is a main isolate in distilled oils from the plants ''Cymbopogon'' (excepting C. citratus, culinary lemongrass), lemon-scented gum, and lemon-scented teatree. The (''S'')-(−)-enantiomer of citronellal makes up to 80% of the oil from kaffir lime leaves and is the compound responsible for its characteristic aroma. Citronellal has insect repellent properties, and research shows high repellent effectiveness against mosquitoes. Another research shows that citronellal has strong antifungal qualities. Compendial status * British Pharmacopoeia See also * Citral * Citronellol * Citronella oil Citronella oilCitronella oil is an essential oil obtained from the leaves and stems of different species of '' Cymbopogon'' (lemongrass). The oil is used extensively as a source of perfumery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trans-2-Methyl-2-butenal
''trans''-2-Methyl-2-butenal is an organic compound with the formula CH3CH=C(CH3)CHO. This colorless liquid is a building block in organic synthesis. It is an α,β-unsaturated aldehyde related to the better-known crotonaldehyde. The European rabbit, ''Oryctolagus cuniculus'', uses 2-methyl-2-butenal as a pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio .... The rabbit pheromone, ''trans''-2-methyl-2-butenal, was reported to be involved in the communication between species, defined under the class of "interomone." References {{DEFAULTSORT:Methyl-2-Butenal, Trans-2- Alkenals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrolein
Acrolein (systematic name: propenal) is the simplest unsaturated aldehyde. It is a colorless liquid with a foul and acrid aroma. The smell of burnt fat (as when cooking oil is heated to its smoke point) is caused by glycerol in the burning fat breaking down into acrolein. It is produced industrially from propene and mainly used as a biocide and a building block to other chemical compounds, such as the amino acid methionine. History Acrolein was first named and characterized as an aldehyde by the Swedish chemist Jöns Jacob Berzelius in 1839. He had been working with it as a thermal degradation product of glycerol, a material used in the manufacture of soap. The name is a contraction of 'acrid' (referring to its pungent smell) and 'oleum' (referring to its oil-like consistency). In the 20th century, acrolein became an important intermediate for the industrial production of acrylic acid and acrylic plastics. Production Acrolein is prepared industrially by oxidation of propene. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methacrylic Acid
Methacrylic acid, abbreviated MAA, is an organic compound with the formula CH2=C(CH3)CO2H. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced industrially on a large scale as a precursor to its esters, especially methyl methacrylate (MMA), and to poly(methyl methacrylate) (PMMA). Production In the most common route, methacrylic acid is prepared from acetone cyanohydrin, which is converted to methacrylamide sulfate using sulfuric acid. This derivative in turn is hydrolyzed to methacrylic acid, or esterified to methyl methacrylate in one step. Another route to methacrylic acid starts with isobutylene, which obtainable by dehydration of ''tert''-butanol. Isobutylene is oxidized sequentially to methacrolein and then methacrylic acid. Methacrolein for this purpose can also be obtained from formaldehyde and ethylene. Yet a third route involves the dehy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturated And Unsaturated Compounds
A saturated compound is a chemical compound (or ion) that resists addition reactions, such as hydrogenation, oxidative addition, and the binding of a Lewis acids and bases, Lewis base. The term is used in many contexts and classes of chemical compounds. Overall, saturated compounds are less reactive than unsaturated compounds. Saturation is derived from the Latin word ''saturare'', meaning 'to fill'.An unsaturated compound is also a chemical compound (or ion) that attracts reduction reactions, such as dehydrogenation,oxidative reduction Organic chemistry Generally distinct types of unsaturated organic compounds are recognized. For hydrocarbons: *alkene (unsaturated) vs alkane (saturated) *alkyne (unsaturated) vs alkane (saturated) *arene (unsaturated) vs cycloalkane (saturated) For organic compounds containing heteroatoms (other than C and H), the list of unsaturated groups is long but some common types are: *carbonyl, e.g. ketones, aldehydes, esters, carboxylic acids (unsatura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde
In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many chemicals important in technology and biology. Structure and bonding Aldehyde molecules have a central carbon atom that is connected by a double bond to oxygen, a single bond to hydrogen and another single bond to a third substituent, which is carbon or, in the case of formaldehyde, hydrogen. The central carbon is often described as being sp2- hybridized. The aldehyde group is somewhat polar. The bond length is about 120–122 picometers. Physical properties and characterization Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes such as formaldehyde and acetaldehyde are solubl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprene
Isoprene, or 2-methyl-1,3-butadiene, is a common volatile organic compound with the formula CH2=C(CH3)−CH=CH2. In its pure form it is a colorless volatile liquid. It is produced by many plants and animals (including humans) and its polymers are the main component of natural rubber. History and etymology Charles Greville Williams, C. G. Williams named the compound in 1860 after obtaining it from the pyrolysis of natural rubber. He correctly deduced the mass shares of carbon and hydrogen (but arrived at an incorrect formula C10H8 because the modern atomic weight of carbon was not adopted until the Karlsruhe Congress held later that year). He did not specify the reasons for the name, but it is hypothesized that it came from "propylene" with which isoprene shares some physical and chemical properties. The first one to observe recombination of isoprene into rubber-like substance was in 1879, and William A. Tilden identified its structure five years later. Natural occurrences Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Vinyl Ketone
Methyl vinyl ketone (MVK, IUPAC name: butenone) is the organic compound with the formula CH3C(O)CH=CH2. It is a reactive compound classified as an enone, in fact the simplest example thereof. It is a colorless, flammable, highly toxic liquid with a pungent odor. It is soluble in water and polar organic solvents. It is a useful intermediate in the synthesis of other compounds. Production MVK has been prepared industrially by the condensation of acetone and formaldehyde, followed by dehydration. Similarly it is prepared by the Mannich reaction involving diethylammonium chloride and acetone, which produces the Mannich adduct: :CH3C(O)CH3 + CH2O + 2NEt2l → H3C(O)CH2CH2N(H)Et2l + H2O Heating this ammonium salt releases the ammonium chloride and the MVK: : H3C(O)CH2CH2N(H)Et2l → CH3C(O)CH=CH2 + 2NEt2l Reactivity and applications MVK can act as an alkylating agent because it is an effective Michael acceptor. It gained early attention for its use in the Robinson ann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is essential in the sense that it contains the essence of the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term "essential" used here does ''not'' mean required or usable by the human body, as with the terms essential amino acid or essential fatty acid, which are so called because they are nutritionally required by a living organism. Essential oils are generally extracted by distillation, often by using steam. Other processes include expression, solvent extraction, '' sfumatura'', absolute oil extraction, resin tapping, wax embedding, and cold pressing. They are used in perfumes, cosmetics, soaps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Sagebrush
'' Artemisia tridentata'', commonly called big sagebrush,MacKay, Pam (2013), ''Mojave Desert Wildflowers'', 2nd ed., , p. 264. Great Basin sagebrush or simply sagebrush (one of several related species of this name), is an aromatic shrub from the family Asteraceae. It grows in arid and semi-arid conditions, throughout a range of cold desert, steppe, and mountain habitats in the Intermountain West of North America. Big sagebrush and other ''Artemisia'' shrubs are the dominant plant species across large portions of the Great Basin. Sagebrush provides food and habitat for a variety of species, such as sage grouse, pronghorn antelope, grey vireo, pygmy rabbit, and mule deer. Several major threats exist to sagebrush ecosystems, including human settlements, conversion to agricultural land, invasive plant species, and wildfires. Native Americans have used the plant medicinally. It is also useful as firewood. Description Big sagebrush is a coarse, many-branched, pale-grey shrub wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. 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 compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
