Monomer
In
chemistry, a
monomer (from
Greek mono "one" and
meros "part") is a small
molecule that may become chemically bonded to other monomers to form a
polymer.
Examples of monomers are
hydrocarbons such as the
alkene and
arene homologous series.Here hydrocarbon monomers such as
styrene and
ethene form polymers used as
plastics like
polystyrene and
polyethene. Other commercially important monomers include acrylic monomers such as
acrylic acid,
methyl methacrylate, and
acrylamide.
Amino acids are natural monomers, and
polymerize to form
proteins.
Glucose monomers can also polymerize to form
starches,
amylopectins and
glycogen polymers. In this case the
polymerization reaction is known as a dehydration or
condensation reaction (due to the formation of
water (H
2O) as one of the products) where a
hydrogen atom and a
hydroxyl (-OH) group are lost to form H
2O and an
oxygen molecule bonds between each monomer unit.
Note that the lower molecular weight compounds built from monomers are also referred to as
dimers,
trimers, tetramers, pentamers,
octamers, 20-mers, etc. if they have 2, 3, 4, 5, 8, or 20 monomer units, respectively. Any number of these monomer units may be indicated by the appropriate prefix, eg,
decamer, being a 10-unit monomer chain or polymer. Larger numbers are often stated in English in lieu of Greek. Polymers with relatively low number of units are called
oligomers.
See also:*
Oligomer*
Polymer*
Polymerization*
Important publications in polymer chemistry
