Ceramics, polymers and composites

What are ceramics?

Non-metallic, inorganic solids made by heating substances to high temperatures.

What are the properties of ceramics?

✅ Hard and brittle
✅ High melting points
✅ Good insulators of heat and electricity
✅ Resistant to corrosion

What is clay?

A natural material made of fine particles of rock that become hard when heated.

Why is clay useful for making pottery and bricks?

✅ It is soft when wet, so it can be shaped.
✅ It hardens when fired at high temperatures.
✅ It is strong and durable when set.

What is glass?

A transparent ceramic made by melting sand (silicon dioxide) and cooling it rapidly.

What are the properties of glass?

✅ Transparent
✅ Hard but brittle
✅ Resistant to chemicals

What are the two main types of glass?

Type of Glass	Composition	Properties	Uses
Soda-lime glass	Sand, limestone, sodium carbonate	Cheaper, easy to shape, brittle	Windows, bottles
Borosilicate glass	Sand, boron trioxide	Higher melting point, resistant to heat	Lab glassware, ovenware

What determines the properties of a polymer?

• Type of monomers used.

• Forces between polymer chains.

What are thermosoftening polymers?

Polymers with weak intermolecular forces between chains, allowing them to melt and reshape when heated.

What are their properties ( thermosoftening)?

✅ Softens when heated.
✅ Easily moulded into new shapes.

What are some uses of thermosoftening polymers?

✅ Plastic bags
✅ Water bottles

What are thermosetting polymers?

Polymers with strong cross-links between chains, making them rigid and heat-resistant.

What are their properties ( thermosetting)?

✅ Does not melt when heated.
✅ Hard and durable.

What are some uses of thermosetting polymers?

✅ Electrical sockets
✅ Cooking pan handles

What is a composite?

A material made by combining two or more materials to improve properties.

How do composites work?

They have:

• Reinforcement (strong material like fibres or fragments).

• Matrix (binder) that holds the reinforcement together.

recall some examples of composites with their properties and uses

Composite	Components	Properties	Uses

Fibreglass

Glass fibres + polymer resin

Strong, lightweight, waterproof

Boats, helmets

Carbon fibre

Carbon fibres + polymer resin

Stronger and lighter than metal

Aerospace, sports cars

Concrete

Cement + sand + gravel + water

Hard, strong under compression

Buildings, bridges

Wood (natural composite)

Cellulose fibres + lignin

Strong, flexible, natural

Furniture, construction