Terylene is a synthetic polymer made by condensation polymerisation. It is used to make clothing and plastic bottles. Explain why Terylene is described as a condensation polymer, and state one property of the monomers that makes condensation polymerisation possible.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Terylene (polyethylene terephthalate, PET) is a widely used synthetic polymer formed from two different monomers. During its manufacture, a small molecule is also produced as a by-product.
Model answer (4 marks)
Terylene is a condensation polymer because the two monomers join together with the loss of a small molecule.
1. During polymerisation each pair of monomers reacts and a small molecule is released.
2. In the case of PET the small molecule lost is water (H₂O).
3. Each monomer contains two functional groups.
4. The two functional groups allow each monomer to link to two others, giving a long chain.
Property of the monomers that makes condensation possible: each monomer has two reactive functional groups (e.g. –COOH and –OH) that can react to form an ester linkage while releasing water.
1. During polymerisation each pair of monomers reacts and a small molecule is released.
2. In the case of PET the small molecule lost is water (H₂O).
3. Each monomer contains two functional groups.
4. The two functional groups allow each monomer to link to two others, giving a long chain.
Property of the monomers that makes condensation possible: each monomer has two reactive functional groups (e.g. –COOH and –OH) that can react to form an ester linkage while releasing water.
Examiner tips
- Use the term ‘condensation polymer’ and mention loss of a small molecule; specify water for PET.
- Show that each monomer has two functional groups and explain how this enables chain growth.
Common mistakes
- Saying the polymer is formed by addition instead of condensation.
- Failing to identify the small molecule released (e.g. not mentioning water).
Mark scheme (4 marks)
- Monomers join together and lose / release a small molecule during the reaction
- The small molecule lost is water (or other valid small molecule e.g. HCl)
- Each monomer must have two functional groups
- Having two functional groups allows each monomer to bond to two other monomers, forming a long chain polymer
Key terms in this question
condensation polymerisation · monomer · polymer
Related
- All Pearson Edexcel International GCSE Chemistry (4CH1) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
More Synthetic polymers questions
- Nylon is a condensation polymer made from two different types of monomer. Explai…
- Poly(propene) and nylon are both synthetic polymers but are made by different ty…
- Poly(chloroethene), also known as PVC, is an addition polymer made from chloroet…
- Addition polymerisation is used to make poly(ethene) from ethene monomers. Descr…