7.3.1-2 - Addition & Condensation Polymerisation

What is a polymer?

A long chain molecule which is made by lots of smaller molecules joining together.

How do molecules containing C=C bond form polymers?

• C=C bonds open up and many smaller molecules (monomers) join together to form a chain (a polymer). No other products are made.

• It’s called an “addition polymerization” reaction.

Give three examples of addition polymers and their uses.

• Polyethene - plastic bags.

• (Poly)tetrafluoroethene (PTFE) - teflon surfaces, for use in non-stick kitchenware.

• (Poly)chloroethene (polyvinylchloride, PVC) - water pipes.

What is a repeating unit of a polymer?

• It is a smallest structure which, upon numerous translations, yields the structure of the polymer.

• In addition polymers: to draw it, take a monomer, change C=C to C-C and show additional single bonds extending away from these carbons.

What is a condensation polymer?

A polymer made in condensation polymerization.

How are condensation polymers made?

In this reaction, many molecules join together; the polymer is formed, but also a small molecule is released, e.g. H2O, HCl.

What are the two main groups of condensation polymers? Name industrially relevant examples.

• Polyesters, e.g. terylene.

• Polyamides, e.g. Nylon.

What is an amide bond?

• Similar to the ester bond, with O replaced by N.

• e.g. (C=O)-NH₂.

• Just like an ester, it contains the C=O group.