Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: State that PET can be converted back into monomers and re-polymerised
Learning Objective/s:
  • Describe the chemical structure of PET and its monomers.
  • Explain why chemical recycling of PET is environmentally important.
  • Compare hydrolysis, glycolysis, and methanolysis routes for PET depolymerisation.
  • Identify the steps required to purify recovered monomers and re‑polymerise them into PET.
  • Evaluate the advantages of chemical recycling over mechanical recycling.
Materials Needed:
  • Projector or interactive whiteboard
  • Slide deck with PET structure and recycling flowchart
  • Handouts summarising recycling methods and equations
  • Sample images of PET bottles and monomer structures
  • Whiteboard and markers
  • Exit ticket slips or online quiz platform
 Introduction:

Begin with a short video showing PET bottles being turned into new plastic, prompting students to consider how this is possible. Review prior knowledge of condensation polymerisation and the structures of ethylene glycol and terephthalic acid. State that by the end of the lesson they will be able to explain how PET can be chemically broken down and rebuilt.
Lesson Structure:
  1. Do‑now (5'): Students list common uses of PET and write the condensation reaction that forms PET.
  2. Mini‑lecture (10'): Present PET’s chemical structure, its monomers, and the environmental importance of recycling.
  3. Guided analysis (12'): Compare hydrolysis, glycolysis, and methanolysis using a table; students complete a worksheet identifying products, conditions, advantages and disadvantages.
  4. Demonstration (8'): Show an animated flowchart of chemical recycling and discuss key reaction conditions.
  5. Group activity (10'): Each group outlines the re‑polymerisation steps for one recycling route and presents its main benefits and challenges.
  6. Check for understanding (5'): Quick Kahoot quiz on monomer recovery and re‑polymerisation.
Conclusion:

Recap that PET can be depolymerised into its original monomers and re‑polymerised to produce material comparable to virgin PET. Students complete an exit ticket describing one recycling method and its primary advantage. For homework, they research a real‑world PET recycling plant and write a short paragraph summarising its process.