Polyvinyl Alcohol


Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Wikipedia.

polyvinyl alcohol

[¦päl·i′vīn·əl ′al·kə‚hȯl]
(organic chemistry)
Water-soluble polymer made by hydrolysis of a polyvinyl ester (such as polyvinyl acetate); used in adhesives, as textile and paper sizes, and for emulsifying, suspending, and thickening of solutions. Abbreviated PVA.

Polyvinyl Alcohol

 

a white solid polymer, [—CH2— CH(OH)—]n, having a degree of polymerization n up to 5,000 and containing as much as 68 percent crystalline phase in the form of microcrystalline formations. Polyvinyl alcohol is nontoxic.

The only practical solvent for polyvinyl alcohol is water. Polyvinyl alcohol does not dissolve in organic solvents and is especially resistant to the action of oils, fats, gasoline, and other hydrocarbons, as well as to the action of dilute acids and alkalies. In industry, polyvinyl alcohol is produced by the saponification of polyvinyl acetate in a methanol solution in the presence of strong acid and alkaline catalysts. Polyvinyl alcohol that contains up to 30 percent residual vinyl acetate monomeric units (solvars or soviols) can be obtained by controlling the degree of saponification.

Polyvinyl alcohol is used in the manufacture of fibers and films. It is also utilized as an emulsifier, thickener, and adhesive. Special brands of polyvinyl alcohol with low molecular weights are important in the food industry and medicine. They are used, for example, as plasma substitutes during blood transfusions and also in drug production.

World production of polyvinyl alcohol in 1973 was about 220,000 tons.

REFERENCES

See references under .

S. S. MNATSAKANOV

References in periodicals archive ?
To prepare composite membranes, BC microfibrils and polyvinyl alcohol (PVA) 4% aqueous solution were very well mixed and then rolled into sheets.
The second method involved adding urea powder to polyvinyl alcohol (PVA) in water solution, and the results were good by measuring the density and surface area, especially when the ratio of polyvinyl alcohol (PVA) is 2%.
Their dress is made polyvinyl alcohol, a biodegradable substance using in washing detergents.
398), Baughman's team spins fibers made of carbon nanotubes and polyvinyl alcohol, a common industrial polymer.
One of these two specimens had been embolized with polyvinyl alcohol (PVA) prior to resection, and it was selected to compare the nature of the different embolic materials.
Chemical offerings delivered and supported locally include epoxy additives and industrial coatings resins, Surfynol and Dynol surfactants, polyurethane chemicals, polyurethane intermediates, alkyl amines, specialty amines and amine derivatives, Airvol polyvinyl alcohol and polymer emulsions.
All grades of Selvol Polyvinyl Alcohol, Selvol Ultiloc, Selvol Ultalux and Selvol Premiol will increase by up to USD130/mt or 110 EUR/mt, added the company.
This 21-micron Bicor MB866 OPP film features a polyvinyl alcohol (PVOH) coating on one side and an acrylic coating on the reverse for packaging of oxygen-sensitive dry products requiring MAP such as fruits and nuts, cereals, snacks, roasted coffees, and pet foods.
Five tenders for the supply of (a) 5 tons mono sodium glutamate, (b) 7 tons PVA - polyvinyl alcohol, (c) homopolymer vinyl acetate, (d) 115 tons potato starch, also (e) about 3,000 tons urea formaldehyde.
Riverdale Capital Ltd (Pinks Sheets: RICP), a developer of its own patented Polyvinyl Alcohol 100 percent biodegradable, non-toxic and water-soluble plastic, has announced cancellation of financing arrangements for the acquisition of Nevada-based WSPVA Bio Products International LLC.
The liquid fabric treatment composition is placed in a water soluble container formed from a water soluble polymer selected from the group consisting of polyvinyl alcohols, polyvinyl alcohol copolymers, partially hydrolyzed polyvinyl acetate, polyvinyl pyrrolidone, alkyl celluloses, ethers and esters of alkyl cellulosics, hydroxyl alkyl, carboxy methyl cellulose sodium, dextrin, maltodextrin, water soluble polyacrylates, water soluble polyacry-lamides and acrylic acid/maleic anhydride copolymers.