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Bisphenol A Controversy
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylmethane
Diphenylmethane is an organic compound with the formula (C6H5)2CH2 (often abbreviated ). The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups. It is a white solid. Diphenylmethane is a common skeleton in organic chemistry. The diphenylmethyl group is also known as '' benzhydryl''. Synthesis It is prepared by the Friedel–Crafts alkylation of benzyl chloride with benzene in the presence of a Lewis acid such as aluminium chloride: :C6H5CH2Cl + C6H6 → (C6H5)2CH2 + HCl Reactivity of the C-H bond The methylene group in diphenylmethane is mildly acidic with a p''K''a of 32.2, and so can be deprotonated with sodium amide. :(C6H5)2CH2 + NH2− → (C6H5)2CH− + NH3 The resulting carbanion can be alkylated. For example, treatment with ''n''-bromobutane produces 1,1-diphenylpentane in 92% yield. :(C6H5)2CH− + CH3CH2CH2CH2Br → (C6H5)2CHCH2CH2CH2CH3 + Br− Alkylation of various benzhydryl compounds has been demonstrated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol C
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol P
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Trioxide
Sulfur trioxide (alternative spelling sulphur trioxide, also known as ''nisso sulfan'') is the chemical compound with the formula SO3. It has been described as "unquestionably the most important economically" sulfur oxide. It is prepared on an industrial scale as a precursor to sulfuric acid. Sulfur trioxide exists in several forms - gaseous monomer, crystalline trimer, and solid polymer. Sulfur trioxide is a solid at just below room temperature with a relatively narrow liquid range. Gaseous SO3 is the primary precursor to acid rain. Molecular structure and bonding Monomer The molecule SO3 is trigonal planar. As predicted by VSEPR theory, its structure belongs to the D3h point group. The sulfur atom has an oxidation state of +6 and may be assigned a formal charge value as low as 0 (if all three sulfur-oxygen bonds are assumed to be double bonds) or as high as +2 (if the Octet Rule is assumed). When the formal charge is non-zero, the S-O bonding is assumed to be delocalized. ... [...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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol M
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol G
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formaldehyde
Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes (). The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Forms Formaldehyde is more complicated than many simple carbon compounds in that it adopts several diverse forms. These compounds can often be used interchangeably and can be interconverted. *Molecular forma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol F
Bisphenol F (BPF; 4,4′-dihydroxydiphenylmethane) is an organic compound with the chemical formula . It is structurally related to bisphenol A (BPA), a popular precursor for forming plastics, as both belong to the category of molecules known as bisphenols, which feature two phenol groups connected via a linking group. In BPF, the two aromatic rings are linked by a methylene connecting group. In response to concern about the health effects of BPA, BPF is increasingly used as a substitute for BPA. Uses BPF is used in the manufacture of plastics and epoxy resins. It is used in the production of tank and pipe linings, industrial flooring, road and bridge deck toppings, structural adhesives, grouts, coatings and electrical varnishes. BPF is also utilized in liners, lacquers, adhesives, plastics, and the coating of drinks and food cans. BPF is found in dental materials, such as restorative materials, liners, adhesives, oral prosthetic devices and tissue substitutes. Biological effect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetaldehyde
Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale in industry. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants. It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body. The International Agency for Research on Cancer (IARC) has listed acetaldehyde as a Group 1 carcinogen. Acetaldehyde is "one of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphenol E
The bisphenols () are a group of chemical compounds related to diphenylmethane. Most are based on two hydroxyphenyl functional groups linked by a methylene bridge. Exceptions include bisphenol S, P, and M. "Bisphenol" is a common name; the letter following denotes the variant, which depends on the additional substituents. Bisphenol A is the most popular representative of the group, often simply called "bisphenol".. List Health effects Bisphenols A (BPA), F (BPF) and S (BPS) have been shown to be endocrine disruptors. Due to its high production volumes, BPA has been characterised as a "pseudo-persistent" chemical, leading to its spreading and potential accumulation in a variety of environmental matrices, even though it has a fairly short half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloral
Chloral, also known as trichloroacetaldehyde or trichloroethanal, is the organic compound with the formula Cl3CCHO. This aldehyde is a colourless oily liquid that is soluble in a wide range of solvents. It reacts with water to form chloral hydrate, a once widely used sedative and hypnotic substance. Production Chloral was first prepared, and named, by the German chemist Justus von Liebig in 1832. Liebig treated anhydrous ethanol with dry chlorine gas. Chloral is produced commercially by the chlorination of acetaldehyde in the presence of hydrochloric acid, producing chloral hydrate. Ethanol can also be used as a feedstock. This reaction is catalyzed by antimony trichloride: :H3CCHO + 3 Cl2 + H2O → Cl3CCH(OH)2 + 3 HCl The chloral hydrate is distilled from the reaction mixture. The distillate is then dehydrated with concentrated sulfuric acid, after which the heavier acid layer (containing the water) is drawn off: :Cl3CCH(OH)2 → Cl3CCHO + H2O The resulting product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
