3.3.12 Polymers

Question 1

What is a condensation reaction

Answer 1

where 2 different monomers with at least 2 functional groups react together, form a link with release of water

Question 2

What are the 3 types of polymers and what are they made from?

Answer 2

Polypeptides - found in proteins
Polyamides - formed from diamine and dicarboxylic acid
Polyesters - formed from diol and dicarboxylic acid

Question 3

What link is formed in polyamides

Answer 3

Amide link

Question 4

Why do we need dicarboxylic acid and diamines?

Answer 4

we need functional groups on either side which is what allows for chains to be formed

Question 5

What is Kevlar and what is it made from?

Answer 5

a polyamide

-used in bulletproof vests, tyres etc

-light weight but strong

made from : benzene-1,4-dicarboxylic acid and 1,4-diaminobenzene

Question 6

draw a repeating unit of kevlar

Question 7

What is nylon 6,6 and what is it made from

Answer 7

a polyamide

• used in ropes, carpets, fabric etc
• made from : hexanedioic acid and 1,6-diaminohexane

Question 8

Draw a repeating unit of nylon 6,6

Question 9

What link is formed to produce a polyester

Answer 9

Ester link

Question 10

What is terylene (PET) and what is it made from

Answer 10

a polyester

• used in plastic drink bottles, sheeting etc
• made from : benzene-1,4-dicarboxylic acid and ethane-1,2-diol

Question 10

What is terylene (PET) and what is it made from

Answer 10

a polyester

• used in plastic drink bottles, sheeting etc
• made from : benzene-1,4-dicarboxylic acid and ethane-1,2-diol

Question 11

Draw a repeating unit of terylene

Question 12

What is hydrolysis of condensation polymers

Answer 12

produce original monomers by addition of water

• find the link, split it down the middle and add OH/H to retrospective monomers

Question 12

What is hydrolysis of condensation polymers

Answer 12

produce original monomers by addition of water

• find the link, split it down the middle and add OH/H to retrospective monomers

Question 13

Why are condensation polymers much better than addition polymers (environmentally)

Answer 13

condensation polymers have polar bonds due to C-O and C-N, so it makes them fairly reactive in water and they can degrade

Question 14

Why are condensation polymers better than addition polymers in terms of features and why?

Answer 14

• 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

Question 15

polymers are useful but their disposal must be carefully managed, what is the difference between disposal of condensation and addition polymers

Answer 15

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

Question 15

polymers are useful but their disposal must be carefully managed, what is the difference between disposal of condensation and addition polymers

Answer 15

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

Question 16

What is landfill used for and why is It bad?

Answer 16

• 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

Question 16

What is landfill used for and why is It bad?

Answer 16

• 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

Question 17

What is incineration and why is it good or bad and how can we reduce the bad effects?

Answer 17

• 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

Question 18

Why is recycling good and how is recycling used?

Answer 18

• 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

Question 19

Compare adv and dis of recycling

Answer 19

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