Search results
Results from the WOW.Com Content Network
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 .
Polyvinyl acetate used further for polyvinyl alcohol is manufactured by radical polymerization in methanol solution. Liquid polybutadienes are made by anionic or radical polymerization in hydrocarbon solutions. Butyl rubber (IIR) by low temperature cationic copolymerization of isobutylene with isoprene in ethylene or methylchloride solution.
Formvar refers to any of several thermoplastic resins that are polyvinyl formals, which are polymers formed from polyvinyl alcohol and formaldehyde as copolymers with polyvinyl acetate. They are typically used as coatings, adhesives, and molding materials. [1]
Many are produced using radical initiators which are produced from organic peroxides. Still others (polystyrene) are produced using anionic initiators such as butyl lithium. An exception from the usual rules, polyvinyl alcohol, (CH 2 CHOH) n, is produced by hydrolysis of polyvinyl acetate. Vinyl alcohol is not sufficiently stable to undergo ...
Some grades of polyvinyl alcohol and other water-soluble polymers can promote emulsion polymerization even though they do not typically form micelles and do not act as surfactants (for example, they do not lower surface tension). It is believed that growing polymer chains graft onto these water-soluble polymers, which stabilize the resulting ...
North Korean men wearing uniforms made from vinylon. Vinylon, also known as Vinalon (more common in Korean sources), is a synthetic fiber produced from reaction between polyvinyl alcohol (PVA) fiber and formaldehyde. Chemically it is polyvinyl formal (PVF). Vinylon was first developed in Japan in 1939 by Ichiro Sakurada, Ri Sung-gi, and H ...
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 ]
For instance, polyvinyl alcohol is (CH 2 CHOH) n with n hydroxyl groups where n can be in the thousands. Cellulose is a polymer with many hydroxyl groups, but it is not referred to as a polyol. Polyols from recycled or renewable sources