Polyvinyl acetate

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2009)

Polyvinyl acetate
IUPAC name	butan-2-yl acetate
Other names	PVAc, PVA
Identifiers
CAS number	9003-20-7 Y
PubChem	7758
SMILES	C=COC(C)=O
Properties
Molecular formula	(C4H6O2)n
Molar mass	86.09 g/mol
Hazards
MSDS	MSDS
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Polyvinyl acetate (PVA or PVAc) is a rubbery synthetic polymer with the formula (C₄H₆O₂)_n.

Preparation

Polyvinyl acetate (PVA or PVAc) is a rubbery synthetic polymer.

• (Homo)polymers are prepared by polymerization of vinyl acetate monomer.
• Copolymers are vinyl acetate (VAM) based polymers internally plasticized with for example ethylene (VAE) or acrylic (VAA).

Polyvinyl acetate is also the raw material to make Polyvinyl alcohol. Polyvinyl acetate is partially or completely hydrolysed. This reverible saponification and esterification reaction was a strong hint for Hermann Staudinger in the formulation of his theory of macromolecules.^[1]

Discovery

Polyvinyl acetate was discovered in Germany in 1912 by Dr. Fritz Klatte. On an industrial scale, vinyl acetate is produced from ethyne, ethanoic acid and a mercury(I) salt.^{[2][verification needed]}

Properties

The degree of polymerization of polyvinyl acetate typically is 100 to 5000. The ester groups of the polyvinyl acetate are sensitive for alkali and will slowly convert PVAc into polyvinyl alcohol and acetic acid.

Under alkaline conditions, boron compounds, such as boric acid or borax causes the polymer to cross-link forming tackifying precipitates or slime.

Applications and uses

As an emulsion in water, PVAc emulsions are used as adhesives for porous materials, particularly for wood, paper, and cloth, and as a consolidant for porous building stone, in particular sandstone.^[3] Uses:

• as wood glue PVAc is known as "white glue" and the yellow "carpenter's glue" or PVA glue.
• in paper converting as fast binding adhesive
• in bookbinding and book arts due to its flexible strong bond and non-acidic nature (unlike many other polymers).
• for handcrafted works.

To a lesser extent PVAc emulsion are used in paper coatings, paint and other industrial coatings. PVA can also be used as coating to protect cheese from fungi and humidity^{[citation needed]}.

See also

• Vinyl acetate
• Polyvinyl alcohol
• Polymerization

References