The Giant Molecules That Shape Our World
🧪 The Giant Molecules That Shape Our World
Think of polymers as molecular LEGO chains! Each LEGO brick is a monomer — small and simple. But connect thousands of bricks together and you can build something enormous and useful. That's exactly what happens when monomers join to make polymers. Two different types of LEGO brick sets exist: addition polymerisation (all same bricks) and condensation polymerisation (two different types of bricks that click and drop a tiny piece when they join).
Polymers are giant molecules made from many small repeating units called monomers. In this topic, we'll explore how alkenes become plastics, why polymers have their unique properties, and the environmental challenges they create.
This topic links directly to alkenes and appears frequently in exam questions about naming polymers, drawing structures, and environmental issues.
Chemistry glossary
- What is a polymer?
- A large molecule made up of many repeating units (monomers) joined together
- What is a monomer?
- A small molecule that can be joined together to form a polymer
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🧠 Memory Aid: ADD vs CONDENSE
The two types of polymerisation are easy to distinguish:
- Addition — alkene opens double bond, chains add together, nothing else produced. Think: ADD = ADD monomer, NOTHING leaves.
- Condensation — two functional groups react, chains join, a small molecule (water) condenses out. Think: CONDENSE = water drops condense out (like water droplets on a cold glass).
Drawing polymers — the four-step checklist:
- Start with the monomer
- Change C=C to C-C (double → single)
- Add continuation lines from each end carbon
- Add brackets with subscript n
Naming polymers: Put the monomer name in brackets with "poly" — ethene → poly(ethene), propene → poly(propene).
Now try it yourself
Quiz · Question 1 of 20
What type of monomers are needed for addition polymerisation?
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This topic in real past papers
Every real exam question we've found on polymers, with a full worked answer.