Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Biodegradable polyesters
18 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →Describe how the biodegradable polyester polylactic acid (PLA) can be made from its monomer, lactic acid. In your answer, state the name of both the process and the type of chemical reaction involved.
Question 2
5 marks · Hard
Answer and see the solution →Polyesters, such as polylactic acid (PLA), often biodegrade more rapidly than addition polymers like poly(ethene).
Answer the following questions about their biodegradability.
(a)[1 mark]Explain what is meant by 'biodegradable polyester'.
(b)[1 mark]State what is meant by an 'ester linkage' in the context of polyester structure.
(c)[3 marks]Compare the biodegradability of polyesters (such as PLA) and addition polymers (such as poly(ethene)).
Explain why polyesters with ester linkages are more biodegradable, referring to the chemical structure and environmental breakdown processes.
Question 3
2 marks · Hard
Answer and see the solution →Lactic acid is the monomer for polylactic acid (PLA). What is the displayed (structural) formula for the part of a PLA chain that is actually repeated in the polymer? Describe or draw the repeat unit of PLA, indicating the ester linkage.