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Bisphenol AF
Bisphenol AF (BPAF) is a fluorinated organic compound that is an analogue of bisphenol A in which the two methyl groups are replaced with trifluoromethyl groups. It exists as a white to light-gray powder. Biological and Chemical Action Bisphenol AF is an endocrine disrupting chemical. Whereas BPA binds with human estrogen-related receptor gamma (ERR-γ), BPAF all but ignores ERR-γ. Instead, BPAF activates ERR-α and binds to and disables ERR-β. The chemical shifts in 1H, 13C and 19F NMR spectroscopy are given in the literature. Applications Bisphenol AF is used as a crosslinking agent for certain fluoroelastomers and as a monomer for polyimides, polyamides, polyesters, polycarbonate copolymers and other specialty polymers. Polymers containing Bisphenol AF are useful in specialties such as high-temperature composites and electronic materials. Industries include cosmetics, chemical manufacturing, production of metals and rubber. It can also be a plastic additive. See als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorinated
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a chemical compound, compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. This kind of conversion is in fact so common that a comprehensive overview is challenging. This article mainly deals with halogenation using elemental halogens (F2, Cl2, Br2, I2). Halides are also commonly introduced using salts of the halides and halogen acids. Many specialized reagents exist for and introducing halogens into diverse substrates, e.g. thionyl chloride. Organic chemistry Several pathways exist for the halogenation of organic compounds, including free radical halogenation, ketone halogenation, electrophilic halogenation, and halogen addition reaction. The nature of the substrate determines the pathway. The facility of halogenation is influenced by the halogen. Fluorine and chlorine are more elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-13 Nuclear Magnetic Resonance
Carbon-13 (C13) nuclear magnetic resonance (most commonly known as carbon-13 NMR spectroscopy or 13C NMR spectroscopy or sometimes simply referred to as carbon NMR) is the application of nuclear magnetic resonance (NMR) spectroscopy to carbon. It is analogous to proton NMR ( NMR) and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms. 13C NMR detects only the isotope. The main carbon isotope, is not detected. Although much less sensitive than 1H NMR spectroscopy, 13C NMR spectroscopy is widely used for characterizing organic and organometallic compounds. Chemical shifts 13C NMR chemical shifts follow the same principles as those of 1H, although the typical range of chemical shifts is much larger than for 1H (by a factor of about 20). The chemical shift reference standard for 13C is the carbons in tetramethylsilane (TMS), whose chemical shift is considered to be 0.0 ppm. ImageSize = width:540 height:440 AlignBars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocrine Disruptors
Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine (or hormonal) systems. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders. Found in many household and industrial products, endocrine disruptors "interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for development, behavior, fertility, and maintenance of homeostasis (normal cell metabolism)." Any system in the body controlled by hormones can be derailed by hormone disruptors. Specifically, endocrine disruptors may be associated with the development of learning disabilities, severe attention deficit disorder, cognitive and brain development problems. There has been controversy over endocrine disruptors, with some groups calling for swift action by regulators to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,2-Bis(4-hydroxyphenyl)propanes
The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline of the text. Some typefaces render it as a small line, slightly curved or straight, but inclined from the vertical. Other fonts give it the appearance of a miniature filled-in figure on the baseline. The comma is used in many contexts and languages, mainly to separate parts of a sentence such as clauses, and items in lists mainly when there are three or more items listed. The word ''comma'' comes from the Greek (), which originally meant a cut-off piece, specifically in grammar, a short clause. A comma-shaped mark is used as a diacritic in several writing systems and is considered distinct from the cedilla. In Byzantine and modern copies of Ancient Greek, the " rough" and "smooth breathings" () appear above the letter. In Latvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol S
Bisphenol S (BPS) is an organic compound with the formula (HOC6H4)2SO2. It has two phenol functional groups on either side of a sulfonyl group. It is commonly used in curing fast-drying epoxy resin adhesives. It is classified as a bisphenol, and a close molecular analog of Bisphenol A (BPA). BPS differentiates from BPA by possessing a sulfone group (SO2) as the central linker of the molecule instead of a dimethylmethylene group (C(CH3)2), which is the case of Bisphenol A. Use BPS is used in curing fast-drying epoxy glues and as a corrosion inhibitor. It is also commonly used as a reactant in polymer reactions. BPS has become increasingly common as a building block in polyethersulfone and some epoxies, following the public awareness that BPA has estrogen-mimicking properties, and widespread-belief that enough of it remains in the products to be dangerous. However, BPS may have comparable estrogenic effects to BPA. BPS is now used to a variety of common consumer products. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol A
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation of phenol and acetone, and has a global production scale which is expected to reach 10 million tonnes in 2022. BPA's largest single application is as a co-monomer in the production of polycarbonates, which accounts for 65–70% of all BPA production. The manufacturing of epoxy resins and vinyl ester resins account for 25–30% of BPA use. The remaining 5% is used as a major component of several high-performance plastics, and as a minor additive in PVC, polyurethane, thermal paper, and several other materials. It is not a plasticizer, although it is often wrongly labelled as such. The health effects of BPA have been the subject of prolonged public and scientific debate. BPA is a xenoestrogen, exhibiting hormone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoroelastomers
{{refimprove, date=June 2008 A fluoroelastomer is a fluorocarbon-based synthetic rubber. Fluroelastomers generally have wide chemical resistance. Composition Several compositions of fluoroelastomers exist including FKM (by ASTM D1418 standard, equivalent to FPM by ISO/DIN 1629 standard); perfluoro-elastomers (FFKM); and tetrafluoro ethylene/propylene rubbers ( FEPM). Performance The performance of fluoroelastomers in aggressive chemicals depends on the nature of the base polymer and the compounding ingredients used for moulding the final products (e.g. O-rings, shaft seals). This performance can vary significantly when end-users purchase polymer containing rubber goods from different sources. Fluoroelastomers are generally compatible with hydrocarbons, but incompatible with ketones such as acetone and organic acids such as acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also writt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMR Spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei. The sample is placed in a magnetic field and the NMR signal is produced by excitation of the nuclei sample with radio waves into nuclear magnetic resonance, which is detected with sensitive radio receivers. The intramolecular magnetic field around an atom in a molecule changes the resonance frequency, thus giving access to details of the electronic structure of a molecule and its individual functional groups. As the fields are unique or highly characteristic to individual compounds, in modern organic chemistry practice, NMR spectroscopy is the definitive method to identify monomolecular organic compounds. The principle of NMR usually involves three sequential steps: # The alignment (polarization) of the magnetic nuclear spins in an applied, constant magnetic field B0. # The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton Nuclear Magnetic Resonance
Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. In samples where natural hydrogen (H) is used, practically all the hydrogen consists of the isotope 1H (hydrogen-1; i.e. having a proton for a nucleus). Simple NMR spectra are recorded in solution, and solvent protons must not be allowed to interfere. Deuterated (deuterium = 2H, often symbolized as D) solvents especially for use in NMR are preferred, e.g. deuterated water, D2O, deuterated acetone, (CD3)2CO, deuterated methanol, CD3OD, deuterated dimethyl sulfoxide, (CD3)2SO, and deuterated chloroform, CDCl3. However, a solvent without hydrogen, such as carbon tetrachloride, CCl4 or carbon disulfide, CS2, may also be used. Historically, deuterated solvents were supplied with a small amount (typically 0.1%) of tetra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen-related Receptor Beta
Estrogen-related receptor beta (ERR-β), also known as ESRRB or NR3B2 (nuclear receptor subfamily 3, group B, member 2), is a nuclear receptor that in humans is encoded by the ''ESRRB'' (Estrogen Related Receptor Beta) gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ... . Function ESRRB has been shown to be vital for the transition between a naïve pluripotent and primed pluripotent state in mammalian cells, and NANOG controls the expression of ESRRB in this scenario. References Further reading * * * * * * * * * * * * * {{Estrogen-related receptor modulators Intracellular receptors Transcription factors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen-related Receptor Alpha
Estrogen-related receptor alpha (ERRα), also known as NR3B1 (nuclear receptor subfamily 3, group B, member 1), is a nuclear receptor that in humans is encoded by the ''ESRRA'' (Estrogen Related Receptor Alpha) gene. ERRα was originally cloned by DNA sequence homology to the estrogen receptor alpha (ERα, NR3A1), but subsequent ligand binding and reporter-gene transfection experiments demonstrated that estrogens did not regulate ERRα. Currently, ERRα is considered an orphan nuclear receptor. Tissue distribution ERRα has wide tissue distribution but it is most highly expressed in tissues that preferentially use fatty acids as energy sources such as kidney, heart, brown adipose tissue, cerebellum, intestine, and skeletal muscle. Recently, ERRα has been detected in normal adrenal cortex tissues, in which its expression is possibly related to adrenal development, with a possible role in fetal adrenal function, in DHEAS production in adrenarche, and also in steroid production of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
