Poly (vinyl acetate) PVA , PVAc , poly (ethenyl ethanoate) : commonly referred to as wood glue , white glue , carpenter glue , school glue , Elmer glue in the US, or PVA glue ) is an aliphatic synthetic polymer of the formula (C 4 H 6 n ) n . It belongs to the polyvinyl ester family, with the general formula - [RCOOCHCH 2 ] -. This is a thermoplastic type.
Video Polyvinyl acetate
Properties
Polymerization rates of poly (vinyl acetate) are typically 100 to 5000, while the ester group is sensitive to alkaline hydrolysis and slowly converts PVAc to polyvinyl alcohol and acetic acid.
PVAc emulsions such as Elmer's Glue-All contain polyvinyl alcohol as protective colloids. Under basic conditions, boron compounds such as boric acid or borax cause polyvinyl alcohols to cross-cross, forming precipitate or toy tools, such as Slime and Flubber.
A number of microorganisms can decrease polyvinyl acetate. Most often, the damage is caused by filamentous fungi - but algae, yeast, mildew, and bacteria can also lower polyvinyl acetate.
Maps Polyvinyl acetate
Discovery
Poly (vinyl acetate) was discovered in Germany in 1912 by Fritz Klatte.
Monomer, vinyl acetate, was first produced on an industrial scale by the addition of acetic acid to acetylene with mercury (I) salt but is now primarily prepared by palladium catalysts of oxidative addition of acetic acid to ethylene.
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PVA is a vinyl polymer. Polyvinyl acetate is prepared by polymerizing vinyl acetate monomers (vinyl free radical polymerization of vinyl acetate monomers).
Apps
As an emulsion in water, PVAc emulsions are used as adhesives for porous materials, especially for wood, paper, and fabrics, and as consolidation for porous building stones, especially sandstone. Use:
- as wood glue, PVAc is known as "white glue" and yellow as "carpenter glue".
- as a paper adhesive during paper packaging conversion
- in the art of bookbinding and books, because of its flexible and non-acidic bonding (unlike many other polymers). The use of PVAc in Archimedes Palimpsest during the 20th century severely hampered the task of dismantling books and preserving and imaging the pages of the early 21st century, in part because glue is stronger than parchment put together.
- in the craft
- as an envelope adhesive
- as wallpaper adhesive
- as primers for drywall and other substrates
PVAc rigid homopolymers, but most of the softer copolymers, a combination of vinyl acetate and ethylene, vinyl acetate ethylene (VAE), are also used in other paper, paint and coating coatings, as binder in woven glass fibers, sanitizing napkins, filter paper and finishing textiles.
Polyvinyl acetate is also a raw material for making other polymers such as:
- Polyvinyl alcohol - [HOCHCH 2 ] -: Polyvinyl acetate is partially or wholly hydrolysed to produce polyvinyl alcohol. This reversible saponification and esterification reaction is a strong indication for Hermann Staudinger in his theoretical formulation of macromolecules. Polyvinyl acetate phthalate (PVAP): Polyvinyl acetate is partially hydrolysed and then esterified with phthalic acid.
See also
- Elmer's Products
- Vinyl acetate
- Polyvinyl alcohol
- Ethylene vinyl acetate
- Polymerization
References
Source of the article : Wikipedia
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