Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Material Science > Chapter 14 > Flashcards

Chapter 14 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Most polymers are considered _____. Which consist of what elements?

A

Hydrocarbons
Hydrogen and Carbon

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the principal characteristic of saturated hydrocarbons?

A

Only single bonds are present.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In saturated hydrocarbons, each carbon has only ___ valence electrons.

A

Four

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In saturated hydrocarbons, carbon’s four valence electrons are ___ bonded to the four other atoms.

A

Singly bonded

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What defines the bonding angles in saturated hydrocarbons?

A

Covalent Bonds.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the simplest hydrocarbon?

A

Methane, CH4

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

With respect to hydrocarbons; if the number of carbon atoms goes up, the boiling point _____.

A

Increases.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Unsaturated hydrocarbons are chemically ____.

A

Reactive.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hydrocarbons that have double or triple bonds are referred to as ____.

A

Unsaturated hydrocarbons.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In saturated vs. unsaturated hydrocarbons, which is the more reactive chemically?

A

Unsaturated Hydrocarbons

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Rank the following in terms of modulus of elasticity with highest at number one and lowest at number 3:

  1. Elastomer
  2. brittle polymer
  3. plastic
A
  1. Brittle polymer
  2. Plastic
  3. Elastomer

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define Isomerism.

A

Two compounds with the same chemical formula that have quite different physical structures.

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Typically isomerism belongs to _____ molecular chains.

A

Longer

Ref: Lecture Notes CH14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What product is polyethylene (PE) used in?

A

Tupperware and other common household plastics. Packaging, grocery bags, children’s toys.

Ref: Wikipedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What product is poly-vinyl chloride (PVC) used in?

A

It’s a common use, very versatile plastic.

My experience: Tubing and plumbing

Ref: Wikipedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What general applications is Polytetrafluoroethylene (PTFE) used in?

A

Teflon Tape, chemically inert pipes, anti-corrosion applications.

Ref: Wikipedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Polypropylene (PP) used in?

A

Common household plastics and packaging.

Ref: Wikipediaa

18
Q

What is polystyrene (PS) generally used for?

A

PS is a hard solid plastic so it can be used in household appliances to gardening (pots and tools) to cups and firmware.

Ref: Wikipedia

19
Q

The extent of polymerization will determine the ___.

A

Molecular weight.

Ref: Lecture Notes CH14

20
Q

What is the key characteristic of polymeric materials?

A

Molecular weight

Ref: Lecture Notes CH14

21
Q

If the polymer chain length is increased, what corresponding change in properties will take place?

A
  1. Increased melting point.
  2. Increased viscosity
  3. Increased impact resistance
  4. Increased strength and toughness

“My Very Independent Idiot.”

Ref: Lecture Notes CH14

22
Q

Give some reason why increasing chain length gives desirable property changes.

A
  1. Increase in chain interactions (van der Waals forces) as the density of entanglements increases.
  2. The presence of number one results in stronger bonding which enables resistance against deformation.

Ref: Lecture Notes CH14

23
Q

What is the “Degree of polymerization?”

A

The average number of repeat units per chain.

Ref: Lecture Notes CH14

24
Q

What are the four main molecular structures for polymers?

A

Linear
Branched
Cross-Linked
Network

“Lary Bought Cable News.”
Ref: Lecture Notes CH14

25
Q

What is “tacticity?”

A

Stereoregularity or the spatial arrangement of free radical units (R) along a chain.

Ref: Lecture Notes CH14

26
Q

In an isotactic configuration, all R groups are on ____.

A

The same side of the chain.

Ref: Lecture Notes CH14

27
Q

In a syndiotactic configuration, all R groups are on ____.

A

Alternate sides of the chain.

Ref: Lecture Notes CH14

28
Q

In an atactic configuration, all R groups are on ____.

A

Radom sides of the chain.

Ref: Lecture Notes CH14

29
Q

What is the difference between cis and trans isomerism?

A

cis- side groups are on the same side of the chain

trans - side groups are on opposite sides of the chain.

Ref: Lecture Notes CH14

30
Q

What is a copolymer?

A

Two or more monomers are polymerized together on the same chain.

Ref: Lecture Notes CH14

31
Q

What are the four types of copolymers?

A
  1. Random
  2. Alternating
  3. Block
  4. Graft

Randy Ate Big Gators.

Ref: Lecture Notes CH14

32
Q

Why are polymers rarely 100% crystalline?

A

It’s extremely difficult for all regions of all chains to become aligned in the same configuration to form crystals.

Ref: Lecture Notes CH14

33
Q

What are the three main families of Polymers?

A
  1. Thermoplastics
  2. Thermosets (resins)
  3. Elastomers.

Ref: Lecture Notes CH14

34
Q

True or False

Thermoplastics can be amorphous or crystalline?

A

True

Ref: Lecture Notes CH14

35
Q

Thermoplastics can be softened when ____, and hardened when ____.

A

Heated
Cooled

Ref: Lecture Notes CH14

36
Q

True or False

Thermoplastics have low strength but are ductile compared to Thermosets.

A

True

Ref: Lecture Notes CH14

37
Q

True or False

Thermosets are NEVER amorphous.

A

False, they are always amorphous.

Ref: Lecture Notes CH14

38
Q

True or False

Thermosets are generally strong and rigid but often brittle.

A

True

Ref: Lecture Notes CH14

39
Q

True or False

The process of heating to soften and cooling to harden Thermoplastics can be extended to thermosets.

A

False, thermosets are crosslinked structures. Once curred the process cannot be reversed.

Ref: Lecture Notes CH14

40
Q

True or False

Elastomers are amorphous in all states.

A

True

Ref: Lecture Notes CH14

41
Q

What is the primary difference between elastomers and thermoset/thermoplastics?

A

Their unique ability to elastically deform by extremely large amounts relative to their undeformed length without any permanent deformation.

An example would be a rubber band.

Ref: Lecture Notes CH14

Material Science (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions