|
Toluol
Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent. As the solvent in some types of paint thinner, permanent markers, contact cement and certain types of glue, toluene is sometimes used as a recreational inhalant and has the potential of causing severe neurological harm. History The compound was first isolated in 1837 through a distillation of pine oil by the Polish chemist Filip Walter, who named it ''rétinnaphte''. In 1841, French chemist Henri Étienne Sainte-Claire Deville isolated a hydrocarbon from balsam of Tolu (an aromatic extract from the tropical Colombian tree '' Myroxylon balsamum''), which Deville recognized as si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalant
Inhalants are a broad range of household and industrial chemicals whose volatile vapors or pressurized gases can be concentrated and breathed in via the nose or mouth to produce intoxication, in a manner not intended by the manufacturer. They are inhaled at room temperature through volatilization (in the case of gasoline or acetone) or from a pressurized container (e.g., nitrous oxide or butane), and do not include drugs that are sniffed after burning or heating. For example, amyl nitrite (poppers), nitrous oxide and toluene – a solvent widely used in contact cement, permanent markers, and certain types of glue – are considered inhalants, but smoking tobacco, cannabis, and crack are not, even though these drugs are inhaled as smoke or vapor. While a few inhalants are prescribed by medical professionals and used for medical purposes, as in the case of inhaled anesthetics and nitrous oxide (an anxiolytic and pain relief agent prescribed by dentists), this article focuse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners ( toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 34,000 in the UK and a further 8,000 abroad. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, China and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Cement
Impact glue, contact glue or neoprene glue, is a type of glue, used mainly to glue plastic foams, laminates, metal panels, etc. . It also allows the mounting of supports of different types (metal on wood, cork on plaster, wood on cement, etc). Contact-type adhesives do not exclusively designate neoprene adhesives, but also all other adhesives characterized by high instant adhesion. Special features Impact glue has a high adhesive capacity, and it is very resistant, it must be applied in thin layers. ''Impact adhesives'' are used in strong bonds with high shear-resistance like laminates, such as bonding Formica to a wooden counter, and in footwear, as in attaching outsoles to uppers. Natural rubber and polychloroprene (Neoprene) are the most commonly used contact adhesives. Both of these elastomers undergo strain crystallization. Contact adhesives must be applied to both surfaces and allowed some time to dry before the two surfaces are pushed together. Some contact adhesives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bounded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For example, protonation of methanol gives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic Aromatic Substitution
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, and alkylation and acylation Friedel–Crafts reaction. Illustrative reactions The most widely practised example of this reaction is the ethylation of benzene. :: Approximately 24,700,000 tons were produced in 1999. (After dehydrogenation and polymerization, the commodity plastic polystyrene is produced.) In this process, acids are used as catalyst to generate the incipient carbocation. Many other electrophilic reactions of benzene are conducted, although on a much smaller scale; they are valuable routes to key intermediates. The nitration of benzene is achieved via the action of the nitronium ion as the electrophile. The sulfonation with fuming sulfuric acid gives benzenesul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auguste André Thomas Cahours
August André Thomas Cahours (1813–1891) was a French chemist and scientist whose contribution to organic chemistry was one of the greatest in history. He discovered, among other things, the processes of synthesis of several chemical molecules, including toluene, xylene, several organo-magnesiums, and derivatives of phosphine and arsine. He was a professor at the École Polytechnique and the École Centrale des Arts et Manufactures. In 1868 he was elected as a member of the Académie des sciences (chemistry section) and in 1880 became a commander of the Légion d'honneur. Sociétés savantes de France Early life Auguste Cahours was born in on 2 October 1813. He was the first of the two children of Rose Adelaide Cartron ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jöns Jacob Berzelius
Baron Jöns Jacob Berzelius (; by himself and his contemporaries named only Jacob Berzelius, 20 August 1779 – 7 August 1848) was a Swedish chemist. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. Berzelius became a member of the Royal Swedish Academy of Sciences in 1808 and served from 1818 as its principal functionary. He is known in Sweden as the "Father of Swedish Chemistry". Berzelius Day is celebrated on 20 August in honour of him. Although Berzelius began his career as a physician, his enduring contributions were in the fields of electrochemistry, chemical bonding and stoichiometry. In particular, he is noted for his determination of atomic weights and his experiments that led to a more complete understanding of the principles of stoichiometry, which is the branch of chemistry pertaining to the quantitative relationships between elements in chemical compounds and chemical reactions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Materials Engineering And Performance
The ''Journal of Materials Engineering and Performance'' is a monthly peer-reviewed scientific journal published by Springer Science+Business Media on behalf of ASM International. The editor-in-chief is Rajiv Asthana ( University of Wisconsin). The journal covers all aspects of materials engineering broadly described as materials selection, design, processing, characterization, and evaluation. The scope includes all substances used in engineering applications with a tendency toward constituent materials that comprise a larger system. Abstracting and indexing This journal is abstracted and indexed by: According to the '' Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.819. References External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myroxylon
''Myroxylon'' is a genus of Fabaceae native to Latin America. History The first described species in this genus was '' M. balsamum.'' It was originally described in 1753 by Linnaeus as ''Toluifera balsamum'', based on a specimen collected in the province of Cartagena (at the time Tolú was located in the province of Cartagena). The genus ''Myroxylon'' was first established by Linnaeus filius in 1781, when he described '' M. peruiferum'' based on a specimen collected by Mutis in South America. Although ''Toluifera'' is prior in term of publication time, ''Myroxylon'' is chosen as the conserved name and ''Toluifera'' is rejected. The name derives from Greek μύρρα (''myrrha'', " myrrh") and ξύλον (''xylon'', " wood"). Species Some authors recognize infra-specific taxa based, mainly, in their balsam phytochemistry; while other authors do not recognize such categories. There are reports of differences in composition of balsams obtained from ''M. balsamum'' var. ''ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tolu Balsam
Tolu balsam or balsam of Tolu is a balsam that originates from South America ( Colombia, Peru, Venezuela). It is similar to (and frequently confounded with) the balsam of Peru. It is tapped from the living trunks of ''Myroxylon balsamum var. balsamum''. The fresh balsam of Tolu is a brownish, sticky, semifluid mass. It gradually becomes a brittle solid, but softens again when it is warm. The balsam contains a fairly large amount of benzyl and cinnamyl esters of benzoic and cinnamic acid (benzyl benzoate, benzyl cinnamate). Collection Balsam of Tolu is obtained by cutting a V-shaped wound on the trunk of ''Myroxylon balsamum'' var. ''balsamum'' and fixing a calabash there to catch the exuded resin. Uses The resin is still used in certain cough syrup formulas. However its main use in the modern era is in perfumery, where it is valued for its warm, mellow yet somewhat spicy scent. It is also used as a natural remedy for skin rashes. It is a well known cause of contact dermat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
