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p-Phenylenediamine (PPD) is an organic compound with the formula C 6 H 4 (NH 2) 2. This derivative of aniline is a white solid, but samples can darken due to air oxidation. [1] It is mainly used as a component of engineering polymers and composites like kevlar. It is also an ingredient in hair dyes and is occasionally used as a substitute for ...
m-Phenylenediamine, also called 1,3-diaminobenzene, is an organic compound with the formula C 6 H 4 (NH 2) 2. It is an isomer of o -phenylenediamine and p -phenylenediamine . This aromatic diamine is a colourless solid that appears as needles, but turns red or purple on exposure to air due to formation of oxidation products. [ 3 ]
Wine is a complex mixture of chemical compounds in a hydro-alcoholic solution with a pH around 4. The chemistry of wine and its resultant quality depend on achieving a balance between three aspects of the berries used to make the wine: their sugar content, acidity and the presence of secondary compounds.
Winemaking conditions that promote exposure to oxygen, such wine barrels kept partially full in order to oxidatively age the wine Aging barrels Aging barrel A barrel, often made of oak, used to age wine or distilled spirits. Alcohol Generally refers to ethanol, a chemical compound found in alcoholic beverages. It is also commonly used to refer ...
Phenylenediamine may refer to: o-phenylenediamine or OPD, a chemical compound C 6 H 4 (NH 2) 2; m-phenylenediamine or MPD, a chemical compound C 6 H 4 (NH 2) 2; p-phenylenediamine or PPD, a chemical compound C 6 H 4 (NH 2) 2; N,N-dimethyl-p-phenylenediamine or DMPD; N,N,N′,N′-tetramethyl-p-phenylenediamine or TMPD, used in microbiology; N,N ...
The effects of autolysis on wine contributes to a creamy mouthfeel that may make a wine seem to have a fuller body. The release of enzymes inhibits oxidation which improves some of the aging potential of the wine. The mannoproteins improve the overall stability of the proteins in the wine by reducing the amount of tartrates that are ...
Tannins are found in the skin, stems, and seeds of wine grapes but can also be introduced to the wine through the use of oak barrels and chips or with the addition of tannin powder. The natural tannins found in grapes are known as proanthocyanidins due to their ability to release red anthocyanin pigments when they are heated in an acidic ...
o-Phenylenediamine (OPD) is an organic compound with the formula C 6 H 4 (NH 2) 2. This aromatic diamine is an important precursor to many heterocyclic compounds. OPD is a white compound although samples appear darker owing to oxidation by air. It is isomeric with m-phenylenediamine and p-phenylenediamine.