3.3.12 - Polymers Flashcards
Name 3 examples of condensation polymers
- polyamides
- polyesters
- polypeptides
What are polyamides made out of?
Dicarboxylic acids + diamines
Polyamides
State the name of the bond that forms between the carboxyl
groups and amino groups
Amide link
Name 2 examples of polyamides
- Nylon 6,6
- Kevlar
State what nylon 6,6 is made from
1,6-diaminohexane + hexanedioic acid
Name some uses of nylon 6,6
Used to make clothing, carpet, rope, airbags and parachutes
Draw an equation showing how nylon 6,6 is formed
State what kevlar is made from
1,4-diaminobenzene and benzene-1,4-dicarboxylic acid
Name some uses of kevlar
Used in bulletproof vests, boat construction, car tyres and lightweight spots equipment
Draw an equation showing how kevlar is formed
What are polyesters made out of?
Dicarboxylic acids + diols
Polyesters
State the name of the bond that forms between the carboxyl
groups and hydroxyl groups
Ester link
Name an example of polyester
Terylene (PET)
State what terylene (PET) is made from
Benzene-1,4-dicarboxylic acid and ethane-1,2diol
Name some uses of terylene (PET)
Used in plastic bottles, clothing, sheets and sails
Draw an equation showing how terylene (PET) is formed
Hydrolysis
Draw the original monomers
Condensation polymers are ______ than addition polymers
stronger & more rigid
Why are condensation polymers stronger & more rigid than addition polymers?
- ∵ made up of chains contains polar bonds e.g. C-N and C-O
- ∴ have Van der Waals forces, permanent dipole-dipole forces and hydrogen bonds between polymer chains
Why are polyalkenes (addition polymers) non-biodegradable and won’t react when being used?
Have non-polar C-C bonds = unreactive and chemically inert
Why are condensation polymers biodegradable?
- polar bonds (e.g. C=O) in chains = open to attack by nucleophiles
- ∴ can be broken down by hydrolysis
- ∴ are biodegradable but process is very slow
Name 3 ways of disposing waste plastics
- Burying in landfill
- Burning as fuel
- Recycling
When are plastics placed in landfills?
When plastic is:
- Difficult to separate from other waste
- Not in sufficient quantities to make separation financially worthwhile
- Too difficult technically to recycle
Name an advantage of using landfills to dispose plastics
Landfill is cheap and easy method of waste disposal
Name 3 disadvantages of using landfills to dispose plastics
- Requires areas of land
- As waste decomposes, can release methane = greenhouse effect
- Leaks from landfill contaminate water supplies
What is an advantage of burning plastics (excluding its cost and ease)?
Heat can be used to generate electricity
Why when burning waste plastics, does the process need to be carefully controlled?
To reduce release of toxic gases
e.g. polymers that contain chlorine (PVC) produce HCl when burned = has to be removed
Burning Waste Plastics
How is the release of toxic gases reduced?
Waste gases from combustion as passed through scrubbers which neutralise gases like HCl by allowing them to react with a base
What is a disadvantage of burning waste plastics?
Waste gases e.g. CO2 will still contributed to greenhouse effect
Name 2 ways to recycle plastics
- Some plastics can be melted and remoulded
- Some plastics can be cracked into monomers & these can be used to make more plastics or other chemicals
Name 4 advantages of recycling waste plastics
- Reduces amount of waste going into landfill
- Saves raw materials, oil = non-renewable
- Cost of recycling plastics is lower than making plastics from scratch
- Produces less CO2 emissions than burning plastic
Name 4 disadvantages of recycling waste plastics
- It is technically difficult to recycle plastics
- Collecting, sorting and processing plastic is more expensive than burning/landfill
- Often can’t remake the plastic you started with, have to make something else
- Plastic can be easily contaminated during the recycling process
Name the molecule
1,4-butanedioic acid
