Chapter 30 - Plastics

Question 1

What are plastics?

Answer 1

Man-made materials, most being made from crude oil

Question 2

What is crude oil?

Answer 2

Crude oil is a thick, black, foul-smelling liquid and is made up of various hydrocarbons which can be separated by fractional distilation

Question 3

Roughly, how much of oil is used to make plastics?

Answer 3

4%

Question 4

Describe the stages of manufacturing plastics from crude oil

Answer 4

1. Simple hydrocarbons are separated from crude oil. These are known as monomers
2. These monomers react together and form long chains called polymers

Question 5

Polymerisation

Answer 5

Small repeating units called monomers join together to form a large molecule called a polymer

Question 6

List some properties of plastics

Answer 6

○Easy to maintain
○Very durable
○Can be molded into almost any shape or size
○Good insulators of heat and electricity
○Easily dyed different colours
○Low densities 
○Cheap

Question 7

Give some uses of polythene

Answer 7

Plastic bags, fertiliser sacks, squeezy bottles, lunch boxes

Question 8

Give reasons for the use of polythene

Answer 8

Strong,cheap,flexible

Question 9

Give some uses of rigid PVC

Answer 9

Pipes and gutters, window frames, floor tiles, curtain rails

Question 10

Give reasons for the use of rigid PVC

Answer 10

Strong, long lasting, weather resistant

Question 11

Give some uses of flexible PVC

Answer 11

Insulation for electrical wires, hosepipes, shower curtains

Question 12

Give reasons for the use of flexible PVC

Answer 12

Strong, long lasting, very flexible

Question 13

Give some uses of polystyrene

Answer 13

Food containers, yoghurt pots, electrical components

Question 14

Give reasons for the use of polystyrene

Answer 14

Strong (but brittle), rigid

Question 15

Give some uses of expanded polystyrene (aeroboard)

Answer 15

Packaging, house wall insulation, disposable coffee cups

Question 16

Give reasons for the use of expanded polystyrene (aeroboard)

Answer 16

Extremely low density, good heat insulator

Question 17

Give some uses of nylon

Answer 17

Tights, carpets, ropes, combs brushes, gear wheels

Question 18

Give reasons for the use of nylon

Answer 18

Can be spun into fibres, hard-wearing

Question 19

Which one? : Most plastics are biodegradable/non-biodegradable

Answer 19

Most plastics are non-biodegradable

Question 20

What happens to plstics when they burn? Give examples

Answer 20

When burned, many dangerous gases are given off. e.g. PVC give off a poisonous hydrogen chloride gas as it burns

Question 21

What are the two reactions plastics have when heated?

Answer 21

Plastics will either

1) melt when heated or
2) not melt or soften when heated