Materials & Polymers

Question 1

What properties do smart materials have?

Answer 1

They have a shape memory, so if you heat it again in water it will turn to its original shape

Question 2

What is an example of a smart material?

Answer 2

Nitinol –> dental braces - the mouth warms it and tries to remember the shape to it gently pulls the teeth with it

Question 3

What are really tiny particles?

Answer 3

Nanoparticles

Question 4

What do nanoparticles include?

Answer 4

Fullerenes

Question 5

What can fullerenes be joined together to make?

Answer 5

Nanotubes

Question 6

What uses to nanoparticles have in nanoscience?

Answer 6

• big surface area to volume- catalysts in industry
• building materials lighter and stronger
• deodorant- does not leave white marks on skin
• nanotubes conduct electricity- used to computer chips

Question 7

What determines the properties of plastics?

Answer 7

The bonds between the different molecules chains

Question 8

What happens if the forces are weak between the chains?

Answer 8

Called thermosoftening polymers - don’t have cross linking between chains therefore the forces are really easy to over come and it’s easy to melt the plastic

Question 9

What happens if the forces are strong between the chains?

Answer 9

Thermosetting polymers have cross links which hold the chains together in a solid structure, therefore they are strong hard and rigid

Question 10

How is low density polythene made?

Answer 10

Heating to about 200 degrees under a high pressure - therefore it’s felxible and made into bottles and plastic bags

Question 11

How is high density polythene made?

Answer 11

Made at a low temperature and pressure - much more rigid and used for water tanks and drainpipes