Give examples of condensation polymers
- Polyamides
- Polyesters
- Polypeptide
What is condensation polymerisation?
- Two different types of monomer, each with at least two functional groups
- Functional group reacts with a group on another monomer to form a link creating polymer chains
- Each time a link is formed, water is lost
Give the equation for the formation of nylon6,6 from 1,6-diaminohexane and hexanedioic acid
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What molecules are polyamides formed from?
dicarboxylic acids and diamines
Give the equation for the formation of kevlar from 1,4-diaminobenzene and benzene-1,4-dicarboxylic acid
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Give the uses of nylon 6,6
- Clothing
- Carpet
- Rope
- Airbags
- Parachutes
Give the uses of Kevlar
- Bullet proof vests
- Boat construction
- Car tyres
- Light weight sports equipment
What molecules make up polyesters
Diols and dicarboxylic acids
Give the equation for the formation of Terylene from benzene-1,4-dicarboxylic acid and ethane1,2-diol
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What process produces original monomers
Hydrolysis
What molecules is needed for the process of hydrolysis?
Water
How are monomers from repeating units drawn?
- Break the chain through the middle bond of the amide or ester link
- Add OH or H to each end of the new molecules
Give the equation to show the formation of a dicarboxylic acid and a diamine from an amide link using water
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What type of bonds are found in condensation polymers?
Polar bonds
Describe the effect of condensation polymers having polar bonds
- They are more stronger and rigid than addition polymers
- So as well as vander waals forces, there are permanent dipole-dipole forces and hydrogen bonds between the polymer chains
Give the advantages and disadvantages of polyalkenes
- They are addition polymers e.g poly(ethene) and polystyrene
- They are non-polar carbon chains which makes them chemically inert and unreactive
- They are non-biodegradable
Give advantages and disadvantages of condensation polymers
- They have polar bonds which makes them open to attack by nucleophiles
- So they can be broken down by hydrolysis so they are biodegradable
- Although the process is very slow
What are the advantages and disadvantages of burying waste plastics
Landfill is used when:
- it is difficult to separate waste plastics form other waste
- not sufficient in quantities to make separation financially worthwhile
- To difficult to technically recycle
- It is cheap and an easy method of waste disposal but requires areas of land
- Waste can decompose and release methane (greenhouse gas), leaks from landfill can also contaminate water supplies
What are the advantages and disadvantages of burning waste plastics
-Waste plastics can be burned and the heat can be used to generate electricity
- This process must be carefully controlled to reduce the the release of toxic gases
- Polymers that contain chlorine produce HCl they burn which needs to be removed
-Waste gases such as carbon dioxide will still contribute to greenhouse effect
- Waste gases from combustion are passed through scrubbers which can neutralise gases such as HCl allowing them to react with a base
What are the advantages of recycling waste plastics
- It reduces the amount of waste going to landfill
- It saves raw materials which is important because oil is non-renewable
- The cost of recycling plastics is lower than making the plastics from scratch
- It produces less CO2 emissions than burning the plastic
What are the disadvantages of recycling waste plastics
- It is technically difficult to recycle plastics
- Collecting, sorting and processing the plastic is more expensive than burning/landfill
- You often can’t remake the plastic you started with- you have to make something else
- The plastic can be easily contaminated during the recycling process
