Polymers: Large Molecules from Monomers

Polymers are large molecules composed of repeating structural units called monomers. The word "polymer" literally means "many parts". These monomers are chemically bonded together to form long chains or networks.

Definition of Polymers

A polymer is a large molecule (macromolecule) consisting of many repeating subunits. These subunits are the monomers.

Formation of Polymers

Polymers are formed through a process called polymerisation. During polymerisation, many monomers join together to form a polymer chain. This process can involve different types of reactions, leading to various types of polymers.

Types of Polymerisation

There are two main types of polymerisation:

• Addition Polymerisation: Monomers add directly to each other without the loss of any atoms. This typically involves monomers with double or triple bonds.
• Condensation Polymerisation: Monomers join together with the loss of a small molecule, such as water.

Examples of Polymers

Many materials we use every day are polymers. Some common examples include:

• Natural Polymers: Starch, cellulose, proteins, DNA
• Synthetic Polymers: Plastics (e.g., polyethylene, PVC), synthetic rubber, nylon, polyester

Table Summarising Polymer Types and Examples

Polymer Type	Monomer Example	Properties	Common Uses
Natural Polymers	Starch	Energy storage in plants, biodegradable	Food, paper
Natural Polymers	Cellulose	Structural component of plants, strong	Textiles, paper, building materials
Synthetic Polymers	Ethylene	Strong, flexible, resistant to chemicals	Plastic bags, bottles, pipes (Polyethylene)
Synthetic Polymers	Vinyl chloride	Hard, durable, resistant to chemicals	PVC pipes, flooring
Synthetic Polymers	Amino acids	Building blocks of proteins, diverse properties	Enzymes, structural proteins

Diagram of Polymer Formation

Key Terms

• Monomer: A small molecule that can bond with other monomers to form a polymer.
• Polymer: A large molecule made up of many repeating monomer units.
• Polymerisation: The process of joining monomers together to form a polymer.
• Addition Polymerisation: Polymerisation where monomers add directly to each other.
• Condensation Polymerisation: Polymerisation where monomers join with the loss of a small molecule.