Learn: Addition polymerisation - Making polymers from alkenes

Welcome!You've already learned about alkenes and their reactions. Today, we'll build on that knowledge to explore addition polymerisation, the process of making polymers from alkenes.

What is addition polymerisation?Addition polymerisation is a chemical reaction where many small alkene molecules (called monomers) join together to form a large molecule called a polymer. This process occurs because alkenes have double bonds that can open up and link together.

Why is addition polymerisation important?Addition polymerisation is used to create materials like plastics, which are widely used in everyday life (e.g., plastic bags, bottles, and packaging). Polymers made from alkenes are strong, flexible, and durable, making them useful for various applications.

How does addition polymerisation work?During polymerisation, the double bond in each alkene molecule breaks open. The monomers then connect together in a repeating chain to form a polymer. For example, ethene molecules can join together to form polyethene.

Examples of polymersDifferent alkenes produce different polymers. For instance, ethene forms polyethene, used in packaging. Propene forms polypropene, used in ropes and containers. Polymers have unique properties based on their structure.

Properties of polymersThe properties of polymers depend on their structure and how their monomers are arranged. For example, polyethene can be made into a flexible material for plastic bags or a harder material for water pipes.

Review Time!Great work! You've learned about addition polymerisation, its process, and examples of polymers. Let's test your understanding with a few questions.