Addition Polymers

Polymers are long molecules made up of hundreds or thousands of repeating subunits.
They are really useful materials for everyday items, such as plastic containers and clothing, but they are a nuisance when it comes to throwing them away because they aren’t broken down easily.

Addition polymers are formed by joining lots of alkene molecules together.
The single alkene is called a monomer and when several monomers are connected together, we call this a polymer.
Polymerisation happens when the double carbon bond breaks, allowing another alkene to connect to the carbon.
This happens multiple times until you end up with a polymer made up of hundreds or thousands of monomers.
- Instead of drawing out a really long chain, it’s much easier to represent polymers by drawing a single subunit (the monomer) inside square brackets, with a little ‘n’ in the right hand corner to show that we have lots of them joined together.
- Remember to draw bonds sticking outside the square brackets to make it clear that the chain continues.
We name the polymer depending on the type of monomer it is made from and stick the word poly at the front.
- Let’s say we have a polymer made up of lots of ethene molecules joined together - this would be called poly(ethene), which we also refer to as polythene.
- Polythene is everywhere - you’ll find it in things like plastic water bottles, bin liners and hose pipes.