A sports clothing company is developing a new fabric using condensation polymerisation. The polymer chain contains amide links formed from monomers with two functional groups. Explain how the structure of the monomers and the nature of the reaction allow a long-chain polymer to form, and state what small molecule is released during the process.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Condensation polymerisation is used to make many synthetic fibres used in the textile industry. Unlike addition polymerisation, condensation polymerisation involves monomers with two functional groups and produces a small molecule as a by-product.
Model answer (5 marks)
Monomers must possess two reactive functional groups, one at each end, so that each can link to two other monomers. The reaction forms an amide bond between the carboxyl group of one monomer and the amine group of another, releasing a small molecule. Because bonds are formed at both ends of every monomer, the chain can grow in both directions, giving a long‑chain polymer. The small molecule lost in each condensation step is water.
Examiner tips
- Show the two functional groups on the monomer; mention amide bond formation; explain bidirectional growth; state water as by‑product; keep answer concise and use correct terminology.
Common mistakes
- Forgetting to mention that each monomer has two functional groups; confusing water with methanol or other by‑products; not explaining bidirectional chain growth; using vague terms like "small molecule" without naming water.
Mark scheme (5 marks)
- Monomers must have two functional groups (one at each end)
- Each monomer can bond to two other monomers / bonds form at both ends of each monomer
- This allows the chain to grow in both directions / produces a long chain polymer
- A small molecule is lost / released each time two monomers join
- The small molecule released is water
Key terms in this question
condensation polymerisation · monomers · functional groups · polymer · amide link
Related
- All OCR A-Level Chemistry A (H432) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
More Nitrogen compounds, polymers and synthesis questions
- Nylon is a condensation polymer made from two different monomers. Explain how co…
- Describe the differences between addition polymerisation and condensation polyme…
- A biochemist is studying the structure of DNA. She notes that DNA is a natural p…
- A food packaging company is researching the use of condensation polymers to crea…