- Not all covalent molecules are small; covalent molecules can also be very large.
- Polymers are very large covalent molecules, sometimes called macromolecules
- Polymers are large molecules of high relative molecular mass and are made by linking together large numbers of smaller molecules called monomers
- Each monomer is a repeat unit and is connected to the adjacent units via strong covalent bonds
- The intermolecular forces acting in between polymer chains are larger than those in between simple molecules so polymers are usually solid at room temperature
- Common polymers include polythene which is used extensively in plastic bags and polyvinyl chloride (PVC) which has many industrial applications, most notably in the production of water pipes.
- Many everyday materials such as resins, plastics, polystyrene cups, nylon etc. are polymers
- These are manufactured and are called synthetic polymers
- Nature also produces polymers which are called natural or biological polymers
- Examples include DNA, proteins, silk and wool
Polymers are made from very long carbon chains with a repeating unit
This diagram shows a short section of polystyrene, a polymer used widely in packaging materials