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Flashcards in Test 1 Deck (11)
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1
Q

What is a thermoset polymer ?

*Also, describe/list several characteristics of a thermoset polymer

A

DEFINITION: polymers that are joined together by chemical bonds acquiring a highly crosslinked polymer structure.

PROPERTIES:

  • cannot be melted
  • insoluble
  • have crosslinks b/t chains
  • doesnt soften when heated
  • do not swell in the presence of certain solvents.
2
Q

What is a thermoplastic polymer?

*Also, describe/list several characteristics of a thermoplastic polymer

A

DEFINITION: a material that becomes soft when heated and hard when cooled.

PROPERTIES:
-Easy to melt
-can be recycled
-can be cooled and heated several times
have very week bonds b/t chains
3
Q

Provide 3 different examples of a natural polymer and explain the key differences between a natural polymer and a synthetic polymer.

A
Polysaccharides(starch, cellulose)
Nucleic acids(DNA, RNA)
Proteins(wool, silk)
4
Q

“… the y-axis is laballed ‘1/(1-p)’, define or explain what the term represents

A

Degree of polymerisation: the average number of monomeric units per molecule(polymer)

5
Q

What is chitosan and provide a structure

A

Chitosan is a linear polysaccharide composed of randomly distributed β–linked D-glucosamine and N-acetyl-D-glucosamine.

6
Q

Would you classify the arrangement of chitosan chains as linear, branched, star-shaped, net-worked, or combed ?

A

linear

7
Q

How would you prepare chitosan

also provide a simple chemical equation

A

Chitin + NaoH —> Chitosan

8
Q

Provide 3 examples for the use of chitosan

A
  • Surfactants and antifoaming agents
  • Hydraulic fluids
  • Skin: dimethicone is used in skin moisturizing lotions
9
Q

What is condensation polymerisation

A

Repetitive condensation between two bifunctional monomers, with loss of some simple molecules such as water, alcohols, etc.

10
Q

What is addition polymerisation and list 3 different types of mechanisms?

A

The addition of monomer units to themselves to form a growing chain by chain reaction mechanisms.

Different types:

  • Anionic
  • Radical
  • Cationic
11
Q

When referring to polymer chemistry, define the ceiling temperature.

A

a measure of the tendency of polymers to revert back to their monomers