What is synthetic rubber?

Synthetic rubber is an artificially produced elastomer material that is characterised by Polymerisation or Copolymerisation of different monomers. The monomers are usually obtained in petrochemical processes from special fractions of crude oil refining. In contrast to natural rubber (NR), which comes from the milky sap of the rubber tree, synthetic rubber is produced in industrial processes under controlled conditions. This allows properties such as Hardness, elasticity, media resistance or temperature behaviour can be specifically adapted to the respective requirements.

 

Production of synthetic rubber

During polymerisation, the monomers (basic units) are linked to form long polymer chains. Important processes are

  • Emulsion polymerisation - e.g. chloroprene rubber (CR) or butadiene rubber (BR)
  • Solution polymerisation - enables more precise control of the molecular structure e.g. butyl rubber (IIR)
  • Copolymerisation - combination of different monomers for targeted property optimisation, e.g. for SBR, NBR or EPDM

 

Classification of synthetic rubber

They are categorised according to the chemical structure of the main polymer chain (DIN/ISO classification):

  • Group R: Unsaturated double bonds in the main chain (NR, SBR, BR, NBR, CR, IIR)
  • Group M: Saturated polymethylene main chain (FKM, EPM, EPDM, CM, CSM, AEM*, ACM, EVM*)
  • Group O: Oxygen in the main chain (polyether rubber) (CO, ECO, GPO)
  • Group U: Nitrogen and oxygen in the main chain (polyurethane rubber) (AU, EU)
  • Group Q: Siloxane groups in the main chain (silicone rubber) (VMQ, MQ, FVMQ)
  • Group T: Sulphur in the main chain (polythioether rubber) (OT, EOT)
  • Group Z: Phosphorus and nitrogen in the main chain (polyphosphazene rubber) (FZ, PZ)

 

* partially saturated copolymers