What is polymerisation?
Polymerisation is a chemical reaction process in which many small molecules (monomers) are linked together to form long, chain-like macromolecules (polymers). This process is the basis for the production of plastics, elastomers and fibres such as polypropylene (PP), polyamide (PA) or rubber types such as NBR, SBR or EPDM.
How does polymerisation work?
During polymerisation, reactive molecules (monomers) react with each other under certain conditions. This produces polymers with very large molecular chains, which give the material its mechanical and thermal properties.
Two main types of polymerisation:
- Chain polymerisation (e.g. with polyethylene, ABS): The polymer chain grows via an active centre. Monomers are added rapidly one after the other along the chain.
- Step polymerisation (e.g. for Polyester, Polyamides): Several small molecules (dimers, oligomers) are formed in stages, which then react further with each other.
A special form of polyreaction is the Copolymerisation, in which a mixture of two or more different monomers is used instead of just one monomer, e.g. in the case of SBR or NBR.
Application and meaning
Polymerisation is the basis for almost all modern plastic and rubber materials: