Polymer and Monomer Simulation — Description
The simulation
Three parallel poly(ethene) chains run side by side in 3D space. Carbon atoms (grey-blue spheres) form the zigzag backbone; hydrogen atoms (smaller cream spheres) branch off each carbon. Yellow lines between the chains represent weak van der Waals forces — the intermolecular forces that hold chains together in the solid polymer.
Four toggles drive the chemistry:
🔗 Monomers separates the chains into individual ethene units (CH₂=CH₂), each showing a C=C double bond in cyan alongside the grey C–C single bond below it. Toggling back animates the monomers closing together, the cyan second bond fading as C–C inter-monomer bonds appear — a direct visual of addition polymerisation.
🌡 Heat makes the outer chains slide in opposite directions past the centre chain, with increasing thermal vibration. The yellow IMF lines stretch visibly as the chains overcome them. This is thermosoftening.
⛓ Cross-links adds bright orange covalent bonds connecting adjacent chains at three points each. Adding Heat on top of Cross-links produces almost no sliding — the contrast with thermosoftening is immediate and dramatic.
🏷 Labels opens the teach panel, which updates its AQA-referenced text in real time depending on which combination of toggles is active.
Hovering (or tapping) any atom shows a tooltip explaining its bonding, geometry change between monomer and polymer, and role in the chain. Projector mode flips to a light background with high-contrast dark atoms.
Suggested classroom activity — “Two Polymers, One Decision”
Suitable for: GCSE Chemistry, Year 10–11 · ~20 minutes · works individually or in pairs
Setup
Display the simulation on the board. Give each student (or pair) a printed decision card with two scenarios:
Scenario A: A company needs a material for saucepan handles. It must withstand 200°C without softening. Scenario B: A company needs a material for plastic carrier bags. It must be cheap, flexible, and recyclable.
Sequence
- Baseline (2 min) — Simulation open, no toggles active. Ask: “What holds these chains together? Is that a strong or weak attraction?” Students annotate the yellow IMF lines on a printed diagram.
- Thermosoftening (5 min) — Teacher presses Heat only. Students observe the chains sliding. Ask: “Which scenario does this polymer suit? Why?” Students write one sentence linking the chain behaviour to the bag use-case.
- Thermosetting (5 min) — Teacher presses Cross-links, then Heat. Students compare the near-zero sliding. Ask: “What is structurally different? Why can’t this polymer be recycled by melting?” Students identify the cross-link bonds on the diagram and label them “covalent.”
- Monomers (3 min) — Teacher presses Monomers to show ethene. Ask: “What feature of the monomer makes addition polymerisation possible?” Students write the equation n(CH₂=CH₂) → (–CH₂–CH₂–)ₙ in their books.
- Exit task (5 min) — Students answer one AQA-style exam question: “Explain, in terms of structure and bonding, why a thermosetting polymer is more suitable than a thermosoftening polymer for use in an electrical plug. [4 marks]”
SEND adaptations built into this activity
- Turn on Labels before Step 2 for students who benefit from on-screen text alongside the visual — the teach panel updates automatically as toggles change, so no separate resource is needed
- Projector mode for students with visual sensitivity to bright screens
- The printed diagram gives a static reference for students who struggle to process animation and text simultaneously
- The decision card frames each toggle as a concrete real-world choice rather than an abstract concept, reducing cognitive load for lower-attaining students
- The exit task is a genuine AQA question, so higher-attaining students can self-assess against the mark scheme immediately after