Chapter 4 - Polymers

Question 1

What is thermosetting?

Answer 1

type of plastic that remains rigid when set and doesn’t soften with heating

Question 2

What is thermosoftening?

Answer 2

type of plastic that always softens on repeated heating

Question 3

Why are thermosetting polymers difficult to melt?

Answer 3

They have strong intermollecular bonds and they’re harder to break chains apart because they’re thermally stable

Question 4

Properties of LDPE:

Answer 4

1. made at temperature of 100 to 300 degrees C and pressure of 1500 to 3000 atmosphere
2. oxide or peroxide initiator used in reaction
3. soft plastic e.g. plactic bags

Question 5

Properties of HDPE:

Answer 5

1. made at temperature of 300 degrees C and pressure of 1 atmosphere
2. aluminium based metal oxide catalyst used in reaction
3. hard plastics e.g. shampoo bottles