In this lesson, we will learn:
- The definitions of polymer, monomer and polymerization.
- To describe the uses of some polymers with examples.
- How to identify the repeating unit and monomer unit when studying a polymer chain.
- Polymers are large molecules made of many repeating smaller units chemically joined together. The word polymer shows this; it has two roots, "poly" meaning many, and "mer" meaning molecule. Most are man-made, but some well-known natural materials are polymers – wool, silk and even DNA in our bodies can be called a polymer!
- The repeating small molecule units that make up the polymer are called monomer units. This word has roots "mono" meaning one, so monomer means "one molecule" where polymer means "many molecules". The most common monomers that make polymers are alkenes, which are mostly sourced from crude oil.
- The most common polymers in our daily lives are man-made and the monomers are alkenes, which have a carbon-carbon double bond. These join together in a chemical process called polymerization, where many small monomers join to make a large combined polymer chain(s).
- Polymers are extremely useful in our daily lives – most plastics are polymers, and their name often begins with poly-. Some include:
- Polyethene (AKA polythene) which is a polymer made of ethene monomer units. Polyethene is used in plastic shopping bags and drinks bottles.
- Polystyrene which is used in packaging materials
- Polychloroethene (AKA polyvinyl chloride; PVC) is used in piping and for electrical wire insulation.
- Identifying polymer molecules is about identifying repeating parts of a larger molecule. See the examples below for identifying and showing polymers, their repeating unit, the monomer structure and their relation to one another: