# Explain how condensation polymerisation produces a polyester, including the type of monomers required and the small molecule that is lost during the reaction.

> AQA GCSE Chemistry (8462) — 4.7.3 Synthetic and naturally occurring polymers (Chem only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Monomers must have two functional groups (dicarboxylic acid and a diol / two different functional groups)
2. Monomers join together / react to form a long polymer chain
3. A small molecule — water — is lost / released during the reaction
4. The polymer contains the ester functional group / ester linkages in its main chain, making it a polyester

## Key terms

- [condensation polymerisation](https://www.gradenine.co.uk/glossary/condensation-polymerisation)
- [polyester](https://www.gradenine.co.uk/glossary/polyester)
- [monomers](https://www.gradenine.co.uk/glossary/monomers)

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-condensation-polymerisation-produces-a-8a857cfb) · Published by Druglandscape Ltd.