Monomer Definition and Examples (Chemistry)

A monomer is a molecule that forms the basic unit for polymers. They may be considered the building blocks from which proteins are made. Monomers may bind to other monomers to form a repeating chain molecule via a process called polymerization. Monomers may be either natural or synthetic in origin.

Oligomers are polymers consisting of a small number (typically under one hundred) of monomer subunits. Monomeric proteins are protein molecules that combine to make a multiprotein complex. Biopolymers are polymers consisting of organic monomers found in living organisms.

Because monomers represent a huge class of molecules, they are commonly categorized. For example, there are sugars, alcohols, amines, acrylics, and epoxides.

The term "monomer" comes from combining the prefix mono-, which means "one", and the suffix -mer, which means "part".

Glucose, vinyl chloride, amino acids, and ethylene are examples of monomers. Each monomer may link in different ways to form a variety of polymers. In the case of glucose, for example, glycosidic bonds may link the sugar monomers to form such polymers as glycogen, starch, and cellulose.

When only a few monomers combine to form a polymer, the compounds have names:

dimer - polymer consisting of 2 monomers
trimer - 3 monomer units
tetramer- 4 monomer units
pentamer- 5 monomer units
hexamer- 6 monomer units
heptamer- 7 monomer units
octamer- 8 monomer units
nonamer- 9 monomer units
decamer- 10 monomer units
dodecamer - 12 monomer units
eicosamer - 20 monomer units