Polymerisation Types
- When a set of monomers are given in an exam question, the type of polymerisation can be determined
- Firstly, it’s important to identify the key functional groups in the monomers
Addition polymerisation
- If the monomer/s contain a C=C double bond, they will polymerise through addition polymerisation
- The double bond can open up in order to add more monomers either side of the starting monomer
- This type of polymerisation makes (poly)alkenes
Addition polymerisation of one alkene monomer is polymerised, a (poly)alkene is formed
- (Poly)alkenes can be produced if there are 2 or more alkene monomers as well
- When more than one monomer is used for addition polymerisation, the resulting product is known as a copolymer
Two or more different alkene monomers can also be polymerised in Addition polymerisation. This gives a co-polymer
Condensation polymerisation
- Condensation polymerisation makes polyamides and polyesters
- When looking to identify this type of polymerisation, there are some key functional groups to be aware of
Monomers for condensation polymers table
Exam Tip
- As well as the functional groups to be aware of, know that a small molecule is expelled when the polymer is formed
- Identify 2 functional groups that can react together to produce either a polyamide or a polyester
- There are instances where both of the functional groups are on the same monomer molecule
- For example amino acid molecules contain an amine group (-NH2) and a carboxylic acid group (-COOH) therefore it can polymerise to produce a polyamide