Composite Materials

Composite Material

Two or more different componenets whose properties compliment each other. Fibre produces support and a liquid matrix is poured around and sets hard. The composite materials will then have properties of both.

Composite material examples with uses and properties

Laminated glass

Rigid and hard wearing but holds together under impact, and can be used for car windscreens. It is made up of glass and a clear polymer, the glass is hard and rigid and the polymer is flexible.

Kevlar

Extremely strong and light. Used for racing cars and speedboat bodies

GRP Glass Reinforced Plastic

Strong, light and slightly flexible. And is often used in boatbuilding. The glass fibres are easily mouled into complex shapes which then sets hard with polymer resin

Concrete vs Cement

Concrete is a mixture of cement, sand, aggregate and water. It is a composite material and is usaully not used in isolation. The amount of aggregate, water, sand and cement plus the type of aggregate and sand will impact the strength of the concrete.

Cement is a dry, powdery substance, when you mix it with water, it can stick things together and is called cement paste, before the water it was weak.

Concrete COTAINS cement.

Limestone

Limestone is a sedimentary rock, it is an important raw material and can be used to make composite materials.

Heat up the limestone to make cement, then you mix in sand and water to make mortar. Then you mix in aggregate and you get concrete.

Places which have a lot of limestone get quarried. When you dig up land for large amount sof limestone or other useful recources like granite, it creates a quarry, this is where you get limestone from.

Thermal decomposition Test 1

Thermal decomposition is when a substance is heated and broken down into simpler and smaller substances.

1. Calcium Carbonate —> Calcium oxide + Carbon dioxide

CaCO3 (small 3)—> CaO+CO2 (small 2)

Limestone is mainly made out of calcium carbonate.

Calcium carbonate has Calcium, carbon and oxygen

This reaction is endothermic.

This first test can be for any metal carbonate

Thermal decomposition Test 2

2. Calcium oxide + Water—> Calcium hydroxide

CaO + H2(small 2)O—> Ca(OH)2 (small 2)

This reaction exothermic

Test for carbon dioxide

1. Bubble the gas into limewater

2. If the gass is CO2(small 2), the limewater will turn from clear to cloudy/milky.

Did you know that when you dissolve Ca(OH)2 (small 2) in water, it becomes limewater!