|
Perfluoroalkyl Carboxylic Acids
Perfluoroalkyl carboxylic acids (PFCAs), or perfluorocarboxylic acids are compounds of the formula CnF(2n+1)CO2H that belong to the class of per- and polyfluoroalkyl substances. The simplest example is trifluoroacetic acid. These compounds are organofluorine analogues of ordinary carboxylic acids, but they are stronger by several pKa units and they exhibit great hydrophobic character. Perfluoroalkyl dicarboxylic acids (PFdiCAs) are also known, e.g. C2F4(CO2H)2. Applications Trifluoroacetic acid is a widely employed acid, used for example in the synthesis of peptides. Its esters are useful in analytical chemistry. Longer-chain perfluoroalkyl carboxylic acids, e.g. with five to nine carbons, are useful fluorosurfactants and emulsifiers used in the production of polytetrafluoroethylene (Teflon) and related fluoropolymers. Production These compounds are typically prepared by electrochemical fluorination of the carboxylic acid fluorides followed by hydrolysis: :CnH(2n+1)COF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorononanoic Acid
Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also a persistent organic pollutant. Chemistry and properties In acidic form it is a highly reactive strong acid. In its conjugate base form as a salt it is stable and commonly ion paired with ammonium. In the commercial product Surflon S-111 (CAS 72968-3-88) it is the primary compound present by weight. PFNA is used as surfactant for the production of the fluoropolymer polyvinylidene fluoride.Supporting Information (PDF) It is produced mainly in Japan by the of a linear |
Geophysical Research Letters
''Geophysical Research Letters'' is a biweekly peer-reviewed scientific journal of geoscience published by the American Geophysical Union that was established in 1974. The editor-in-chief iKristopher Karnauskas Aims and scope The journal aims for rapid publication of concise research reports on one or more of the disciplines covered by the American Geophysical Union, such as atmospheric sciences, solid Earth, space science, oceanography, hydrology, land surface processes, and the cryosphere. The journal also publishes invited reviews that cover advances achieved during the past two or three years. The target readership is the earth science community, the broader scientific community, and the general public. Abstracting and indexing This journal is abstracted and indexed in: According to the 2020 ''Journal Citation Reports'', the journal has a 2019 impact factor of 4.58. ''Geophysical Research Letters'' was also the 5th most cited publication on climate change Pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per- And Polyfluoroalkyl Substances
Per- and polyfluoroalkyl substances (also PFAS, PFASs, and informally referred to as "forever chemicals") are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain; there are 7 million known such chemicals according to PubChem. PFAS came into use with the invention of Teflon in 1938 to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. They are now used in products including waterproof fabric such as Nylon, yoga pants, carpets, shampoo, feminine hygiene products, mobile phone screens, wall paint, furniture, adhesives, food packaging, firefighting foam, and the insulation of electrical wire. PFAS are also used by the cosmetic industry in most cosmetics and personal care products, including lipstick, eye liner, mascara, foundation, concealer, lip balm, blush, and nail polish. Many PFAS such as PFOS and PFOA pose health and environmental concerns because they are persi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorodecanoic Acid
Perfluorodecanoic acid (PFDA) is a fluorosurfactant and has been used in industry. PFDA is a member of the group of polyfluoroalkyl substances (PFAS), more specific is it also a perfluoroalkyl acid (PFAA). PFAS, like PFDA, are man-made and are not naturally occurring in nature. Over the last decades they have been used in consumer products and industrial applications. It is a fluorosurfactant with a unique hydrophobicity and oleophobicity.Iris assessments. Perfluorodecanoic Acid (PFDA). Available via PFDA is well resistant to heat, oil, stains, grease and water, therefore it has been used in stain and greaseproof coating for furniture, packaging and carpet. Next to that, PFDA has also been found in nano-and impregnation-sprays, outdoor textiles, gloves, ski wax, leather, cosmetics, medical equipment and paper-based food containers. PFDA has a relatively high toxicity and can promote tumor growth. It was recently linked to health concerns, like other fluorosurfactants, leading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorooctanoic Acid
Perfluorooctanoic acid (PFOA; conjugate acid, conjugate base perfluorooctanoate; also known colloquially as C8, from its chemical formula C8HF15O2) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a chemical precursor. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, ''n''-heptyl "tail group" and a carboxylic acid "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic. The International Agency for Research on Cancer (IARC) has classified PFOA as carcinogenic to humans. PFOA is one of many synthetic organofluorine compounds collectively known as per- and polyfluoroalkyl substances (PFASs). Many PFAS such as Perfluorooctanesulfonic acid, PFOS, PFOA are a concern because they do not break down via natural processes and are commonly described as persistent organic pollutants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorohexanoic Acid
Perfluorohexanoic acid (PFHxA) is a fluorinated carboxylic acid derivative of hexanoic acid. Fluorinated polymers with six carbon or less commonly degrade into perfluorohexanoic acid. Perfluorohexanoic acid does not seem to persistently bioaccumulate in the manner of many other PFAS. For example, in a study sponsored by the Swedish EPA, Swedish ski wax technicians, who have high PFAS exposure, did not have significantly higher levels of PFHxA in their blood samples when compared to the general population median for their age groups, even while having concentrations of other PFAS, like PFOA, up to 44 times higher than the general population. In 2020 Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ... adopted drinking water standards for five previously unregulated PFAS comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluoropropanoic Acid
Perfluoropropionic acid (PFPrA) or pentafluoropropionic acid is an ultra-short chain perfluoroalkyl carboxylic acid with the formula CF3CF2CO2H. It is a colorless liquid that is strongly acidic. It soluble in both water and polar organic solvents. The compound is produced by electrochemical fluorination of the carboxylic acid or its acid fluoride derivative. It has a predicted pKa of 0.38, with an uncertainty of 0.10. In many ways, it is comparable to trifluoroacetic acid. Occurrence and use The perfluoropropanoate form has been found in environmental samples. A convenient laboratory method for generating tetrafluoroethylene is the pyrolysis of the 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 Neutra ... of pentafluoropropionic acid:{{cite journal , doi = 10.1016/j.jfluche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Weight
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (molecule), water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Formula
A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name since it does not contain any words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called '' empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of atoms of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urethane SCFP Hydrolysis Simplified
Urethane may refer to: *Ethyl carbamate, a chemical compound which is an ester of carbamic acid *Polyurethane, a polymer composed of a chain of organic units joined by carbamate (urethane) links *Carbamate, an organic compound derived from carbamic acid See also *Acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ... * Cetone {{Disambiguation Science disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
