Chemguide: Support for CIE A level Chemistry


Learning outcomes 21.2(a) and 21.2(b)

These statements are about the relationship between the monomers, the polymer chain and the type of polymerisation - addition or condensation.

Before you go on, you should find and read the statement in your copy of the syllabus.


These statements are fairly simple, and ask you to predict either:

  • what sort of polymerisation (addition or condensation) will result from given monomers;

  • what sort of polymerisation (addition or condensation) gave a particular polymer structure.


Predictions about addition polymerisation

Starting from the monomer(s)

If your monomer contains carbon-carbon double bonds, then it will undergo addition polymerisation.

It is possible that you might be given two different compounds containing carbon-carbon double bonds as a pair of monomers. These are known as copolymers. They will still undergo addition polymerisation, but the polymer will obviously be more complicated than if you polymerised just ethene, for example.

Copolymers aren't mentioned anywhere in the syllabus, but are discussed in the teacher support material.

This has all been covered in statements 15.2(e) and15.2(f).


Starting from the polymer

If the main chain of the polymer contains only carbon atoms, then it must be an addition polymer.


Predictions about condensation polymerisation

Starting from the monomer(s)

If the monomer or monomers don't contain carbon-carbon double bonds, then it is condensation polymerisation. Look for groups that you know are involved in this. These could be -OH and -COOH or -COCl for polyesters. Or they could be -NH2 and -COOH or -COCl for polyamides.


Starting from the polymer

If the main chain of the polymer contains nitrogen or oxygen atoms, then it must be a condensation polymer.


Go to the Section 21 Menu . . .

To return to the list of learning outcomes in Section 21

Go to the CIE Main Menu . . .

To return to the list of all the CIE sections

Go to Chemguide Main Menu . . .

This will take you to the main part of Chemguide.


© Jim Clark 2011 (last modified June 2014)