9Polymers

Question 1

A high # of low mw molecules OR a low # of high mw molecules may have the same average mw but have _______ ________!

Answer 1

Different Properties!

Question 2

What is the property of polymers that softening happens during heating and hardening happens during cooling?

Answer 2

ThermoPlastic

Question 3

___________ do NOT soften on heating and are termed ________.

Answer 3

CROSS LINKED POLYMERS……ThermoSET

Question 4

What are the three stages of Free Radical Polymerization?

Answer 4

1.Initiation 2.Propagation 3.Termination

Question 5

Which stage creates free radicals (molecules with unshared electrons)?

Answer 5

1. Initiation Stage

Question 6

Which stage is activated monomer molecules attacking double bonds of other monomers and chains grow in length?

Answer 6

2. Propagation Stage

Question 7

Which stage are materials like hydroquinone, eugenol or large amounts of oxygen inhibiting or retarding polymerization by reacting with free-radicals?

Answer 7

3. Termination Stage

Question 8

Polymers absorb _______.

Answer 8

Moisture