Polymers Flashcards
What is a polymerisation reaction?
involves joining small monomers into polymers
Why are addition polymers/polyalkenes non biodegradable
due to non-polar covalent bonds between atoms in polymers
C-C bonds are non-polar so they are not susceptible to attack by nucleophiles therefore aren’t easily hydrolysed
What forces are present in addition polymers
Van der Waals
What is a condensation reaction?
joins two molecules together
involves elimination of small molecule (often water)
How are amides formed
reaction between acyl chlorides and an amine
How are condensation polymers formed
from monomers with functional groups at both ends
What are the condensation polymers
- polyester
- polyamides
How can you form a polyester
- joining a diacid and a diol
- joining a diacyl and a diol
How do you draw a repeating unit of polyester made with a diacid and diol
remove an OH from the molecule on the left and remove a H from the molecule on the right
- 2 waters are removed
Name and describe a polyester
Terylene
made from benzene-1,4-dioic acid & ethane-1,2-diol
How do you draw a repeating unit of a polyester made with a diacyl and diol
Remove the Cl from the acyl and remove a H from the diol
- 2 HCl are removed
How are polyamides formed?
- from a diacid and diamine
- from a diacyl and diamine
Name and describe 2 Polyamides
Nylon 6.6
- made from hexane dioic acid and hexane-1,6-diamine
Kevlar
- made frombenzene-1,4-dioic acid and benzene-1,4-diamine
What are properties of condensation polyamides
possess IMF which are strengthened by hydrogen bonds
so they are very strong
some natural polyamides (proteins) can form helical structures
What are the uses of polyamides and polyesters
- used in high strength synthetic fibres
- used as wool and cotton substitutes
- polyesters are used in bullet proof vests and flame resistant clothing
- polyamides are more elastic and used in underwear and other synthetic fibres
Why are polyesters and polyamides biodegradable?
the C=O/C-N bonds in the polymer chain are polar
How are addition polymers disposed of
disposed in landfill sites some are melted and remoulded
How are polyalkenes disposed of
burnt to produce CO2 and water to produce energy
- but CO2 is toxic and Carbon (black soot) may also be produced if combustion is incomplete
What are advantages of recycling polymers
- came from crude oil which is non renweable
- reduces landfil
What are disadvantages of recycling polymers
- plastics need to be collected and transported which uses energy and man power
- expensive
What IMF are present in polyesters
Dipole dipole forces
What IMF are present in polyamides
hydrogen bonds
