3.3.12 Polymers Flashcards
What is a condensation reaction
where 2 different monomers with at least 2 functional groups react together, form a link with release of water
What are the 3 types of polymers and what are they made from?
Polypeptides - found in proteins
Polyamides - formed from diamine and dicarboxylic acid
Polyesters - formed from diol and dicarboxylic acid
What link is formed in polyamides
Amide link
Why do we need dicarboxylic acid and diamines?
we need functional groups on either side which is what allows for chains to be formed
What is Kevlar and what is it made from?
a polyamide
-used in bulletproof vests, tyres etc
-light weight but strong
made from : benzene-1,4-dicarboxylic acid and 1,4-diaminobenzene
draw a repeating unit of kevlar
What is nylon 6,6 and what is it made from
a polyamide
- used in ropes, carpets, fabric etc
- made from : hexanedioic acid and 1,6-diaminohexane
Draw a repeating unit of nylon 6,6
What link is formed to produce a polyester
Ester link
What is terylene (PET) and what is it made from
a polyester
- used in plastic drink bottles, sheeting etc
- made from : benzene-1,4-dicarboxylic acid and ethane-1,2-diol
What is terylene (PET) and what is it made from
a polyester
- used in plastic drink bottles, sheeting etc
- made from : benzene-1,4-dicarboxylic acid and ethane-1,2-diol
Draw a repeating unit of terylene
What is hydrolysis of condensation polymers
produce original monomers by addition of water
- find the link, split it down the middle and add OH/H to retrospective monomers
What is hydrolysis of condensation polymers
produce original monomers by addition of water
- find the link, split it down the middle and add OH/H to retrospective monomers
Why are condensation polymers much better than addition polymers (environmentally)
condensation polymers have polar bonds due to C-O and C-N, so it makes them fairly reactive in water and they can degrade
Why are condensation polymers better than addition polymers in terms of features and why?
- they are more ridgid and stronger than addition polymer counterparts
- hydrogen bonds, dipole-dipole and van der Waals forces exist between polymer chains (due to the polar bonds and interactions between adjacent chains)
- hence making them stronger than addition polymers
polymers are useful but their disposal must be carefully managed, what is the difference between disposal of condensation and addition polymers
CP: e.g polyamides, they are polar and susceptible to attack from nucleophiles so they are biodegradable and broken down by hydrolysis slowly
AP : e.g polyethene, they are saturated and non-polar hence unreactive. they are good when used with foods as they dont redact but they dont degrade well in landfill
polymers are useful but their disposal must be carefully managed, what is the difference between disposal of condensation and addition polymers
CP: e.g polyamides, they are polar and susceptible to attack from nucleophiles so they are biodegradable and broken down by hydrolysis slowly
AP : e.g polyethene, they are saturated and non-polar hence unreactive. they are good when used with foods as they dont redact but they dont degrade well in landfill
What is landfill used for and why is It bad?
- used for disposing plastics that cant be recycled, difficult to serrate from other materials, not enough plastic to make it economically viable
- as waste decomposes in landfill, it makes methane (greenhouses) and risk of water contamination from waste leaching
-not sustainable as large land needed, increasingly expensive to use land for waste
What is landfill used for and why is It bad?
- used for disposing plastics that cant be recycled, difficult to serrate from other materials, not enough plastic to make it economically viable
- as waste decomposes in landfill, it makes methane (greenhouses) and risk of water contamination from waste leaching
-not sustainable as large land needed, increasingly expensive to use land for waste
What is incineration and why is it good or bad and how can we reduce the bad effects?
- burning of waste plastic if cant be recycled
- good as energy from burning can produce electricity
- bad as it can release toxic fumes e.g HCL when PVC is burned
- flue gas scrubbers used to neutralise acidic gases (HCL) by spraying base at flue gases
Why is recycling good and how is recycling used?
- reduces crude oil use as plastics are made from crude oil but by recycling the plastic there is less dependancy on crude oil
- some plastics e.g poly(ethene) can be remoulded
- some plastics are cracked into monomers and used as ORGANIC FEEDSTOCK for other plastics etc
Compare adv and dis of recycling
ADV:
- cheaper to recycle plastics than make from scratch
- less co2
- reduces reliance on landfill
- preserves non-renewable material
DIS:
- plastics can be contaminated
- wide variety so difficult to recycle
- hard to make OG plastic from recycled material
- sorting and processing plastics expensive compared to burning
