Polymers

Question 1

What determines the properties of plastics?

Answer 1

The forces between molecules.

Question 2

What type of polymers have weak forces? Why?

Answer 2

Thermosoftening polymers. They don’t have cross-links between the molecule chains so the forces are easy to overcome. They can be remoulded overtime they are heated.

Question 3

What type of polymers have strong forces? Why?

Answer 3

Thermosetting polymers. They have cross-linking between the molecule chains so there is a solid structure, and the forces are hard to overcome. Once set in a mould after heating, they can’t be softened or remoulded.

Question 4

What also affects its properties?

Answer 4

How you make them.

Question 5

What are the two types of polythene and what are they used for?

Answer 5

1) low density polythene is made by heating ethene at 200C under high pressure, used for bags and bottles as it is flexible
2) high density polythene is made at a lower temperature and pressure (catalyst), used for drainpipes and water tanks as it is more rigid