Chapter 25- Macromolecules

• Macromolecule: A long chain molecule containing hundreds of atoms joined together by covalent bonds. It is also called a polymer.

• Monomers: Small repeating units that join to form a macromolecule.

• Polymerisation: the process of joining together a large number of monomers to make a polymer.

• Addition polymeristion: the type of polymeristion where no atoms are lost so just one product is formed.

• Condensation polymeristion: the type of polymerisation where a small molecule, usually water, is also produced as a byproduct.

ADDITION POLYMERISATION

• At high temperature and pressure, thousands of alkenes join together to form an addition polymer.

• The double bonds in monomers break at such high temperature and pressure, forming single bonds with two other monomers.

• Ethene is used to manufacture the polymer, poly(ethene), commonly known as polythene.

• Addition polymers are used to make disposable containers, PVC pipes, raincoats and gloves etc.

CONDENSATION POLYMERISATION

• There are two groups of condensation polymers: polyamides and polyesters.

Nylon is made from diamine and dicarboxylic acid.

Terylene is made from diol and dicarboxylic acid.

• Plastics and polymers are non-biodegradable and cause pollution problems.