Polymers

Question 1

Forces between _______ determine the properties of plastics.

Answer 1

Molecules.

Question 2

Can chains of polymers held together by weak intermolecular forces slide over each other?

Answer 2

Yeah because the intermolecular forces are WEAK so they are free to move.

Question 3

Can chains of polymers held together by strong intermolecular forces slide over each other?

Answer 3

No, because they’re held together by strong intermolecular forces called crosslinks.

Question 4

What’s the difference between thermosoftening polymers and thermosetting polymers?

Answer 4

Thermosetting polymers have crosslinks made of strong intermolecular bonds.

Question 5

Features of Thermosoftening Polymers?

Answer 5

Weak intermolecular forces are easy to overcome so it’s easy to melt plastics made from these polymers. When it cools, the plastic hardens into a new shape.

Question 6

Features of Thermosetting Polymers?

Answer 6

Strong intermolecular forces make these plastics have very strong structures, the polymer doesn’t soften when heated. They’re hard, strong and rigid.

Question 7

Which two things affect the properties of a polymer?

Answer 7

Reaction conditions and starting materials.

Question 8

What are the 2 types of polythene?

Answer 8

High Density Polythene & Low Density Polythene

Question 9

What is low density polythene?

Answer 9

It’s made at about 200 degrees celsius under high pressure, it’s flexible and is used for bags and bottles.

Question 10

What is high density polythene?

Answer 10

It’s made at lower temperatures and pressure (with a catalyst). It’s more rigid and is used for water tanks and drainpipes.