Monomer
The small molecule that repeats to form a polymer.
Unit
g/mol
In depth
A monomer must be at least bifunctional — carrying a double bond for addition polymerisation or two reactive groups for condensation. Monomer choice determines the properties of the resulting material, and even trace impurities can terminate chains and ruin a polymerisation.
Examples in the real world
Ethene giving polythene; amino acids giving proteins; glucose giving cellulose.