01
True or false
1 point
In a semicrystalline polymer, the melting temperature marks the melting of its ordered regions.
Free Practice Quiz Question List
05 Polymer Materials Online Quiz Questions
Use this free practice quiz with 20 questions to review 05 Polymer Materials, test your knowledge, and prepare for your next test or exam.
20 questions
02
Fill in the blank
1 point
A polymer's repeating chemical units are derived from smaller molecules called .
03
Written response
1 point
What process is commonly used to cross-link natural rubber?
04
Choose one
1 point
Which molecular structure best explains why a thermoplastic can soften and flow when heated to a suitable temperature?
- A
A permanently cross-linked network that degrades before it can flow
- B
Separate, uncross-linked chains that can soften and flow when heated suitably
- C
Flexible chains that can stretch but cannot be reshaped by heating
- D
Ordered regions that prevent the material from softening
05
True or false
1 point
Once cured, a thermoset can be reheated until it melts and flows into a new shape.
- A
True
- B
False
06
Choose one
1 point
What does it mean for a polymer to be semicrystalline?
- A
It contains only disordered chains.
- B
It consists entirely of ordered regions.
- C
It contains both ordered regions and amorphous material.
- D
Its chains are all permanently joined into a thermoset network.
07
Written response
1 point
Below its glass-transition temperature, an amorphous polymer may be prone to what kind of failure?
08
Fill in the blank
1 point
A viscoelastic polymer's response depends on both the and the of an applied load.
09
Choose all
1 point
Select all statements that describe elastomers.
- A
They can undergo large, mostly recoverable deformations.
- B
Their chains are permanently locked into a rigid network with no ability to extend.
- C
Their flexible chains can uncoil and extend under tension.
- D
A small number of cross-links or physical junctions help prevent permanent slipping and support recovery.
10
Choose one
1 point
What structural change occurs in a thermoset during curing?
- A
It forms a network of chains joined by permanent covalent cross-links.
- B
It breaks every chain into separate monomers.
- C
It makes the chains uncross-linked so they can slide freely when heated.
- D
It creates only ordered regions that melt at the glass-transition temperature.
11
Choose all
1 point
Select all material-and-application pairings supported by the material.
- A
Polyethylene for a lightweight, chemically resistant container
- B
An appropriate grade of polycarbonate for a rigid, transparent component
- C
An elastomer for a flexible seal
- D
Epoxy resin for a structural adhesive
- E
Phenolic resin for a product that must stretch greatly and recover like rubber
12
Open ended
1 point
A design team assumes that every polymer must be less stiff and less strong than every metal. Explain why this assumption is too broad, using the material's qualification about polymer performance.
13
True or false
1 point
Every polymer is guaranteed to have lower density and greater corrosion resistance than every metal.
- A
True
- B
False
14
Choose one
1 point
An amorphous polymer is heated from below its glass-transition temperature to above it, without reaching a temperature that causes degradation. What change in behavior is most likely?
- A
It becomes harder and more brittle.
- B
It becomes more flexible or rubbery.
- C
Its chains become permanently cross-linked.
- D
Its ordered regions melt.
15
Written response
1 point
What symbol denotes the glass-transition temperature of a polymer?
16
Choose one
1 point
In a polymer, what do weaker attractions between neighboring chains most directly affect?
- A
The strength of covalent bonds along each chain
- B
The chemical identity of the monomers
- C
How easily neighboring chains slide past one another
- D
Whether the polymer contains monomers
17
Choose one
1 point
A polymer has been cured into a permanent covalently cross-linked network. What should a designer expect if it is reheated after curing?
- A
It softens and flows so it can be reshaped repeatedly.
- B
It does not melt and flow again; excessive heat eventually degrades it.
- C
It becomes an uncross-linked thermoplastic.
- D
It becomes a semicrystalline polymer as soon as it is heated.
18
Written response
1 point
What term describes a polymer that contains both ordered regions and amorphous material?
19
Choose one
1 point
Why do elastomers have a small number of cross-links or physical junctions?
- A
They limit permanent chain slippage and help the material recover when the load is removed.
- B
They prevent chains from extending under tension.
- C
They make the polymer melt and flow after curing.
- D
They turn flexible chains into ordered regions.
20
Choose one
1 point
Which description best identifies a thermoplastic?
- A
A permanent network that cannot melt and flow again
- B
Flexible chains with limited cross-links that allow large recoverable deformation
- C
Separate, uncross-linked chains that can soften when heated
- D
Chains joined by permanent cross-links only after melting