# Describe the differences between addition polymerisation and condensation polymerisation, including the types of monomers involved and any small molecules produced.

> OCR A-Level Chemistry A (H432) — 6.2 Nitrogen compounds, polymers and synthesis · Describe · 5 marks

> Polymers are large molecules made by joining many smaller monomer units together. There are two main types of polymerisation reaction studied in chemistry.

## Mark scheme (5 marks)

1. Addition polymerisation uses monomers with a carbon–carbon double bond (alkenes / unsaturated monomers)
2. In addition polymerisation no small molecules are produced / only the polymer is formed
3. Condensation polymerisation uses monomers that each have two functional groups
4. In condensation polymerisation a small molecule (such as water) is lost / released when monomers join
5. Addition polymerisation forms a polymer from a single type of monomer whereas condensation polymerisation often involves two different types of monomer

## Key terms

- [addition polymerisation](https://www.gradenine.co.uk/glossary/addition-polymerisation)
- [condensation polymerisation](https://www.gradenine.co.uk/glossary/condensation-polymerisation)
- [monomer](https://www.gradenine.co.uk/glossary/monomer)
- [polymer](https://www.gradenine.co.uk/glossary/polymer)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-differences-between-addition-polymerisation-3e584a3b) · Published by Druglandscape Ltd.