Monomer Monomer May 7 Category="Polymer chemistry"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. In addition, Lipids are formed from monomers of fatty acids and glycerol.

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 (H₂O) as one of the products) where a Hydrogen atom and a hydroxyl (-OH) group are lost to form H₂O 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.