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Recrystallization: In analytical and synthetic chemistry work, purchased reagents of doubtful purity may be recrystallised, e.g. dissolved in a very pure solvent, and then crystallized, and the crystals recovered, in order to improve and/or verify their purity.
Chloroform, [10] or trichloromethane (often abbreviated as TCM), is an organochloride with the formula C H Cl 3 and a common solvent.It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and PTFE. [11]
Cure monitoring is, for example, an essential component for the control of the manufacturing process of composite materials. The material, initially liquid, at the end of the process will be solid: viscosity is the most important property that changes during the process. Cure monitoring relies on monitoring various physical or chemical properties.
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
In organic chemistry, neighbouring group participation (NGP, also known as anchimeric assistance) has been defined by the International Union of Pure and Applied Chemistry (IUPAC) as the interaction of a reaction centre with a lone pair of electrons in an atom or the electrons present in a sigma or pi bond contained within the parent molecule but not conjugated with the reaction centre.
AST was defined as a biochemical marker for the diagnosis of acute myocardial infarction in 1954. However, the use of AST for such a diagnosis is now redundant and has been superseded by the cardiac troponins. [21] Laboratory tests should always be interpreted using the reference range from the laboratory that performed the test.
As cyanoacrylates age, they polymerize, become thicker, and cure more slowly. They can be thinned with a cyanoacrylate of the same chemical composition with lower viscosity. [31] Storing cyanoacrylates below 0 °F (−18 °C) will nearly stop the polymerization process and prevent aging.
Polyaspartic ester chemistry was first introduced in the early 1990s making it a relatively new technology. [1] [2] [3] The patents were issued to Bayer in Germany and Miles Corporation in the United States. It utilizes the aza-Michael addition reaction. [4] [5] These products are then used in coatings, adhesives, sealants and elastomers. [6]