Polymers Flashcards
Why are plastics not biodegradable?
The C-C backbone is not reactive.
The bonds are non-polar and are not susceptible to attack by nucleophiles or enzymes. The bonds cannot be hydrolysed.
How do addition polymers form?
Formed when alkenes polymerise
Describe condensation polymers:
Polymers formed from a condensation reaction between monomers that have 2 reactive ends.
A dicarboxylic acid + a diol makes…
A polyester and water
How do you form a polyamide?
dicarboxylic acid + diamine –> polyamide + water
diacyl chloride + diamine –> polyamide + HCL
What are some uses of nylon?
Strong and resistant to abrasion
- Ropes
- Tights
- Webbing
- Strong twine for fabric repairs
What are the uses of kevlar?
Light and very strong
- Bullet proof vests
- Tyres
Why are nylon and kevlar so strong?
Many hydrogen bonds between molecules that require a lot of energy to separate.
What are the uses of terylene:
Stable at both cold and hot temperatures
What are the 2 polyamides you need to know?
Kevlar
Nylon
What is the polyester you need to know?
Terylene
How do we hydrolyse polyamides and polyesters?
polyamides - acids
polyesters - alkali
Why are condensation polymers biodegradable but addition polymers are not?
Condensation polymers can undergo hydrolysis due to their polar carbonyl group.
In addition polymers C-C bonds are non-polar and so they are not susceptible to attack by nucleophiles or enzymes.
How many hydrogen bonds does adenine and thymine form?
2
How many hydrogen bonds does guanine and cytosine form?
3
