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Glycolide
Glycolide (1,4-dioxane-2,5-dione) is a dimer of glycolic acid. Its structure is six-membered ring containing two lactones, an oxidized variant of ''p''-dioxane. The compound can be synthesized from glycolic acid, via a high-temperature oligomerization to form polyglycolide followed by a depolymerization process. A more direct method is by self-condensation of the sodium salt of chloroacetic acid Chloroacetic acid, industrially known as monochloroacetic acid (MCA), is the organochlorine compound with the formula . This carboxylic acid is a useful building block in organic synthesis. It is a colorless solid. Related compounds are dichlo .... It is useful as a starting material for the production of polyglycolide. References Dimers (chemistry) Lactones Dioxanes {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyglycolide
Polyglycolide or poly(glycolic acid) (PGA), also spelled as polyglycolic acid, is a biodegradable, thermoplastic polymer and the simplest linear, aliphatic polyester. It can be prepared starting from glycolic acid by means of polycondensation or ring-opening polymerization. PGA has been known since 1954 as a tough fiber-forming polymer. Owing to its hydrolytic instability, however, its use was slow to develop. Polyglycolide and its copolymers ( poly(lactic-''co''-glycolic acid) with lactic acid, poly(glycolide-''co''-caprolactone) with ε-caprolactone and poly (glycolide-''co''-trimethylene carbonate) with trimethylene carbonate) are widely used as a material for the synthesis of absorbable sutures and are being evaluated in the biomedical field. Physical properties Polyglycolide has a glass transition temperature between 35 and 40 °C and a melting point in the range of 225 to 230 °C. PGA also exhibits an elevated degree of crystallinity, around 45–55%, thus r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycolic Acid
Glycolic acid (or hydroxyacetic acid; chemical formula ) is a colorless, odorless and hygroscopic crystal, crystalline solid, highly solubility, soluble in water. It is used in various skin care, skin-care products. Glycolic acid is widespread in nature. A glycolate (sometimes spelled "glycollate") is a Salt (chemistry), salt or ester of glycolic acid. History The name "glycolic acid" was coined in 1848 by French chemist Auguste Laurent (1807–1853). He proposed that the amino acid glycine—which was then called ''glycocolle''—might be the amine of a hypothetical acid, which he called "glycolic acid" (''acide glycolique''). Glycolic acid was first prepared in 1851 by German chemist Adolph Strecker (1822–1871) and Russian chemist Nikolai Nikolaevich Sokolov (1826–1877). They produced it by treating hippuric acid with nitric acid and nitrogen dioxide to form an ester of benzoic acid and glycolic acid (), which they called "benzoglycolic acid" (''Benzoglykolsäure''; also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimer
Dimer may refer to: * Dimer (chemistry), a chemical structure formed from two similar sub-units ** Protein dimer, a protein quaternary structure ** d-dimer ** TH-dimer * Dimer model, an item in statistical mechanics, based on ''domino tiling'' * Julius Dimer (1871–1945), German chess master See also * Dimery (botany), having two parts in a distinct whorl of a plant structure * Di (other), a prefix * Dymer (other) * -mer, a suffix * Oligomer In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.Quote: ''Oligomer molecule: A molecule of intermediate relativ ... * Peierls transition, sometimes called dimerization {{Disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactone
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresponding hydroxycarboxylic acids. Nomenclature Greek alphabet#Letters, Greek prefixes in alphabetical order indicate ring size. Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone. The first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, and so forth. Therefore, the prefixes also indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Redox Reaction
Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. In organic chemistry oxidations and reductions are different from ordinary redox reactions, because many reactions carry the name but do not actually involve electron transfer.March Jerry; (1985). Advanced Organic Chemistry reactions, mechanisms and structure (3rd ed.). New York: John Wiley & Sons, inc. Instead the relevant criterion for organic oxidation is gain of oxygen and/or loss of hydrogen.''Organic Redox Systems: Synthesis, Properties, and Applications'', Tohru Nishinaga 2016 Simple functional groups can be arranged in order of increasing oxidation state. The oxidation numbers are only an approximation: When methane is oxidized to carbon dioxide its oxidation number changes from −4 to +4. Classical reductions include alkene reduction to alkanes and classical oxidations include oxidation of alcohols to aldehydes. In oxidations electrons are r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligomer
In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular mass.'' The name is composed of Greek elements '' oligo-'', "a few" and '' -mer'', "parts". An adjective form is ''oligomeric''. The oligomer concept is contrasted to that of a polymer, which is usually understood to have a large number of units, possibly thousands or millions. However, there is no sharp distinction between these two concepts. One proposed criterion is whether the molecule's properties vary significantly with the removal of one or a few of the units. An oligomer with a specific number of units is referred to by the Greek prefix denoting that number, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depolymerization
Depolymerization (or depolymerisation) is the process of converting a polymer into a monomer or a mixture of monomers. This process is driven by an increase in entropy. Ceiling temperature The tendency of polymers to depolymerize is indicated by their ceiling temperature. At this temperature, the enthalpy of polymerization matches the entropy gained by converting a large molecule into monomers. Above the ceiling temperature, the rate of depolymerization is greater than the rate of polymerization, which inhibits the formation of the given polymer. Applications Depolymerization is a very common process. Digestion of food involves depolymerization of macromolecules, such as proteins. It is relevant to Plastic recycling, polymer recycling. Sometimes the depolymerization is well behaved, and clean monomers can be reclaimed and reused for making new plastic. In other cases, such as polyethylene, depolymerization gives a mixture of products. These products are, for polyethylene, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Salt
Sodium salts are salt (chemistry), salts composed of a sodium cation and any anion. The anion may be the conjugate base of some Inorganic compound, inorganic or organic acids, or any monatomic or polyatomic anion. They can be formed by the Neutralization (chemistry), neutralization of acids with sodium hydroxide. Categorization Sodium salts can be categorized into: *sodium salts of carboxylic acids (e.g. sodium formate, HCOONa, the sodium salt of formic acid, and sodium acetate, CH3COONa, the sodium salt of acetic acid, etc.) and *sodium salts of inorganic acids (sulfonic acids, etc.) Organic sodium salts Drugs In pharmaceutical technology acidic pharmaceutical substances are often converted into sodium salts, because they are more stable, more soluble or membrane-permeable (bioavailable) than the base compound. Examples of such sodium salts are (selection): Bispyribac, bithionol, bosentan, brequinar, bromfenac, Cefmenoxime, ceftiofur, citicoline, cromolyn, diclofenac, Fluclox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroacetic Acid
Chloroacetic acid, industrially known as monochloroacetic acid (MCA), is the organochlorine compound with the formula . This carboxylic acid is a useful building block in organic synthesis. It is a colorless solid. Related compounds are dichloroacetic acid and trichloroacetic acid. Production Chloroacetic acid was first prepared (in impure form) by the French chemist Félix LeBlanc (1813–1886) in 1843 by chlorinating acetic acid in the presence of sunlight, and in 1857 (in pure form) by the German chemist Reinhold Hoffmann (1831–1919) by refluxing glacial acetic acid in the presence of chlorine and sunlight, and then by the French chemist Charles Adolphe Wurtz by hydrolysis of chloroacetyl chloride (), also in 1857. Chloroacetic acid is prepared industrially by two routes. The predominant method involves chlorination of acetic acid, with acetic anhydride as a catalyst: : This route suffers from the production of dichloroacetic acid and trichloroacetic acid as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimers (chemistry)
Dimers is a sports betting analytics platform that provides predictive tools, data-driven insights, news, and betting content for sports fans and bettors. Operating under the umbrella of Cipher Sports Technology Group, Dimers has offices in Melbourne and New York. History Dimers.com was launched on August 1, 2020, shortly after its parent company Cipher Sports Technology Group was formed through the merger of two Australian companies: iRival Media and Hypometer Technologies. iRival Media, founded in October 2019 by Adam Fiske and Nick Slade, focused on delivering content to the sports betting market.Hypometer Technologies, established in 2015 by Katie Prowd and Darryl Woodford, specialized in predictive analytics and machine learning for sports. Dimers’ data has been cited by publications such as ''Sports Illustrated,'' ''USA Today,'' and ''The Arizona Republic ''The Arizona Republic'' is an American daily newspaper published in Phoenix. Circulated throughout Arizo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactones
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Lactones are formed by lactonization, the intramolecular esterification of the corresponding hydroxycarboxylic acids. Nomenclature Greek prefixes in alphabetical order indicate ring size. Lactones are usually named according to the precursor acid molecule (''aceto'' = 2 carbon atoms, ''propio'' = 3, ''butyro'' = 4, ''valero'' = 5, ''capro'' = 6, etc.), with a ''-lactone'' suffix and a Greek letter prefix that specifies the number of carbon atoms in the heterocycle — that is, the distance between the relevant -OH and the -COOH groups along said backbone. The first carbon atom after the carbon in the -COOH group on the parent compound is labelled α, the second will be labeled β, and so forth. Therefore, the prefixes also indicate the size of the lactone ring: α-lactone = 3-membered ring, β-lactone = 4-membered, γ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
