Polyvinyl acetate (PVA, PVAc, poly(ethenyl ethanoate)), commonly known as wood glue, PVA glue, white glue, carpenter's glue, school glue, or
Elmer's glue in the US, is a widely available adhesive used for porous materials like wood, paper, and cloth. An
aliphatic rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, a ...
y
synthetic polymer
Some familiar household synthetic polymers include: Nylons in textiles and fabrics, Teflon in non-stick pans, Bakelite for electrical switches, polyvinyl chloride (PVC) in pipes, etc. The common PET bottles are made of a synthetic polymer, polye ...
with the formula (C
4H
6O
2)
''n'', it belongs to the
polyvinyl ester family, with the general formula β
COOCHCH2. It is a type of
thermoplastic.
Properties
The
degree of polymerization of polyvinyl acetate is typically 100 to 5000, while its
ester group
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
s are sensitive to
base hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolysi ...
and slowly convert PVAc into
polyvinyl alcohol and
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...
.
The
glass transition temperature of polyvinyl acetate is between 30 and 45 Β°C depending on the molecular weight.
PVAc dispersions such as
Elmer's Glue-All contain polyvinyl alcohol as a protective colloid. In alkaline conditions,
boron compounds such as
boric acid or
borax cause the polyvinyl alcohol to
cross-link, forming tackifying precipitates or toys, such as
Slime and
Flubber.
A number of microorganisms can degrade polyvinyl acetate. Most commonly, damage is caused by filamentous
fungi
A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...
; however,
algae
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...
,
yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to consti ...
s,
lichens, and
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...
can also degrade polyvinyl acetate.
Discovery
Polyvinyl acetate was discovered in
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
in 1912 by
Fritz Klatte.
The monomer,
vinyl acetate, was first produced on an industrial scale by the addition of
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...
to
acetylene with a mercury(I) salt, but it is now primarily made by
palladium-catalyzed oxidative addition of
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...
to
ethylene.
Preparation
PVA is a
vinyl polymer. Polyvinyl acetate is prepared by the
polymerization of
vinyl acetate monomer
Vinyl acetate is an organic compound with the formula CH3CO2CH=CH2. This colorless liquid is the precursor to polyvinyl acetate and ethene-vinyl acetate copolymers, important industrial polymers.
Production
The worldwide production capacity of ...
(
free-radical vinyl polymerization of the
monomer vinyl acetate).
Applications
As a
dispersion in water (usually an emulsion), PVAc preparations are used as
adhesives for
porous materials, particularly for
wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of ligni ...
,
paper, and
cloth, and as a consolidant for porous building stone, in particular
sandstone.
Uses:
* As
wood glue, PVAc is known as "white glue" and the yellow as "carpenter's glue".
* As paper adhesive during paper packaging conversion.
* In
bookbinding and book arts, due to its flexible strong bond and non-
acidic nature (unlike many other polymers). The use of PVAc on the
Archimedes Palimpsest during the 20th century greatly hindered the task of disbinding the book and preserving and imaging the pages in the early 21st century, in part because the glue was stronger than the parchment it held together.
* In
handicrafts
A handicraft, sometimes more precisely expressed as artisanal handicraft or handmade, is any of a wide variety of types of work where useful and decorative objects are made completely by oneβs hand or by using only simple, non-automated re ...
.
* As
envelope adhesive.
* As
wallpaper adhesive Adhesive flakes that are mixed with water to produce wallpaper paste
Wallpaper adhesive or wallpaper paste is a specific adhesive, based on modified starch, methylcellulose, or clay used to fix wallpaper to walls.
Wallpaper pastes have a typica ...
.
* As a
primer for
drywall and other substrates
* As a gum base in
chewing gum.
* As an adhesive for
cigarette paper.
*As the coating layer on Gouda cheese.
The stiff
homopolymer PVAc, but mostly the softer
copolymer, a combination of vinyl acetate and ethylene,
vinyl acetate ethylene (VAE), is also used in
paper coatings,
paint and other industrial coatings, as a binder in
nonwovens in
glass fibers,
sanitary napkins
A menstrual pad, or simply a pad, (also known as a sanitary pad, sanitary towel, sanitary napkin or feminine napkin) is an absorbent item worn by women in their underwear when menstruating, bleeding after giving birth, recovering from gyneco ...
,
filter paper and in
textile finishing.
Polyvinyl acetate is also the raw material to make other polymers like:
*
Polyvinyl alcohol β
OCHCH2: Polyvinyl acetate is partially or completely
hydrolysed to give polyvinyl alcohol. This reversible saponification and esterification reaction was a strong hint for
Hermann Staudinger in the formulation of his theory of
macromolecules.
[H. Staudinger, K. Frey, W. Stark, Ber. Deut. Chem. Ges. 1927, 60, 1782.]
*
Polyvinyl acetate phthalate (PVAP): Polyvinyl acetate is partially hydrolyzed and then esterified with
phthalic acid.
See also
*
Ethylene vinyl acetate
*
International Klein Blue
*
Elmer's Products
References
{{Authority control
Adhesives
Household chemicals
Vinyl polymers
Woodworking adhesives
Wood finishing materials
Polymers
Acetate esters