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Polyvinyl alcohol (PVOH, PVA, or PVAl) is a water-soluble synthetic polymer. It has the idealized formula [CH 2 CH(OH)] n. It is used in papermaking, textile warp sizing, as a thickener and emulsion stabilizer in polyvinyl acetate (PVAc) adhesive formulations, in a variety of coatings, and 3D printing. It is colourless (white) and odorless.
Vinyl alcohol, also called ethenol (IUPAC name; not ethanol) or ethylenol, is the simplest enol. With the formula C H 2 CH O H , it is a labile compound that converts to acetaldehyde immediately upon isolation near room temperature. [ 1 ]
Ethylene vinyl alcohol (EVOH) is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde , the copolymer is prepared by polymerization of ethylene and vinyl acetate to give the ethylene vinyl acetate (EVA) copolymer followed by hydrolysis.
Vinyl polymers are subject of several structural variations, which greatly expands the range of polymers and their applications. With the exception of polyethylene, vinyl polymers can arise from head-to-tail linking of monomers, head-to-head combined with tail-to-tail, or a mixture of those two patterns. Additionally the substituted carbon center in such polymers is stereogenic (a "chiral center")
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Yalda Night, or Shab-e Yalda (also spelled Shabe Yalda), marks the longest night of the year in Iran and in many other Central Asian and Middle Eastern countries. On the winter solstice, in a ...
The "Alternatives to Detention" program is tracking more than 25,000 migrants using ankle and wrist-worn monitors, which costs taxpayers an average of nearly $80,000 each day, according to ICE data.
Polyethylene vinyl acetate has recently become a popular alternative to polyvinyl chloride because it does not contain chlorine. [13] As of 2014, EVA has not been found to be carcinogenic by the NTP , ACGIH , IARC , or OSHA , and has no known adverse effect on human health. [ 14 ]