Flashcards in Test 1 Deck (11):
What is a thermoset polymer ?
*Also, describe/list several characteristics of a thermoset polymer
DEFINITION: polymers that are joined together by chemical bonds acquiring a highly crosslinked polymer structure.
-cannot be melted
-have crosslinks b/t chains
-doesnt soften when heated
-do not swell in the presence of certain solvents.
What is a thermoplastic polymer?
*Also, describe/list several characteristics of a thermoplastic polymer
DEFINITION: a material that becomes soft when heated and hard when cooled.
-Easy to melt
-can be recycled
-can be cooled and heated several times
have very week bonds b/t chains
Provide 3 different examples of a natural polymer and explain the key differences between a natural polymer and a synthetic polymer.
Nucleic acids(DNA, RNA)
"... the y-axis is laballed '1/(1-p)', define or explain what the term represents
Degree of polymerisation: the average number of monomeric units per molecule(polymer)
What is chitosan and provide a structure
Chitosan is a linear polysaccharide composed of randomly distributed β--linked D-glucosamine and N-acetyl-D-glucosamine.
Would you classify the arrangement of chitosan chains as linear, branched, star-shaped, net-worked, or combed ?
How would you prepare chitosan
(also provide a simple chemical equation)
Chitin + NaoH ---> Chitosan
Provide 3 examples for the use of chitosan
*Surfactants and antifoaming agents
*Skin: dimethicone is used in skin moisturizing lotions
What is condensation polymerisation
Repetitive condensation between two bifunctional monomers, with loss of some simple molecules such as water, alcohols, etc.
What is addition polymerisation and list 3 different types of mechanisms?
The addition of monomer units to themselves to form a growing chain by chain reaction mechanisms.