# A research chemist is investigating the production of nylon-6,6, a polyamide used in the manufacture of ropes and parachutes. Explain how nylon-6,6 is formed by condensation polymerisation, including the role of the functional groups on the monomers and the small molecule produced during the reaction.

> OCR A-Level Chemistry B: Salters (H433) — 6.2 Nitrogen compounds, polymers and synthesis · Explain · 5 marks

> Nylon-6,6 is a polyamide synthesised from two monomers: a diamine and a dicarboxylic acid. Each monomer contains two functional groups. The polymer chains are long and strong, making nylon suitable for high-tension applications such as climbing ropes.

## Mark scheme (5 marks)

1. Condensation polymerisation involves monomers joining together and losing (releasing) small molecules
2. The small molecule released is water
3. Each monomer must have two functional groups (bifunctional) so that the chain can grow in both directions / polymerisation can continue
4. The amine functional group (–NH2) reacts with the carboxylic acid functional group (–COOH) to form an amide (–CO–NH–) linkage / peptide bond
5. The process repeats many times to produce a long polymer chain

## Key terms

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

## Related

- [Revision notes for OCR A-Level Chemistry B: Salters (H433)](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/a-research-chemist-is-investigating-the-a6812e02) · Published by Druglandscape Ltd.