3.12 Polymers

Question 1

Name 3 examples of condensation polymers

Answer 1

• polyamides
• polyesters
• polypeptides

Question 2

What are polyamides made out of?

Answer 2

Dicarboxylic acids + diamines

Question 3

Polyamides

State the name of the bond that forms between the carboxyl
groups and amino groups

Answer 3

Amide link

Question 4

Name 2 examples of polyamides

Answer 4

1. Nylon 6,6
2. Kevlar

Question 5

State what nylon 6,6 is made from

Answer 5

1,6-diaminohexane + hexanedioic acid

Question 6

Name some uses of nylon 6,6

Answer 6

Used to make clothing, carpet, rope, airbags and parachutes

Question 7

Draw an equation showing how nylon 6,6 is formed

Answer 7

Question 8

State what kevlar is made from

Answer 8

1,4-diaminobenzene and benzene-1,4-dicarboxylic acid

Question 9

Name some uses of kevlar

Answer 9

Used in bulletproof vests, boat construction, car tyres and lightweight spots equipment

Question 10

Draw an equation showing how kevlar is formed

Answer 10

Question 11

What are polyesters made out of?

Answer 11

Dicarboxylic acids + diols

Question 12

Polyesters

State the name of the bond that forms between the carboxyl
groups and hydroxyl groups

Answer 12

Ester link

Question 13

Name an example of polyester

Answer 13

Terylene (PET)

Question 14

State what terylene (PET) is made from

Answer 14

Benzene-1,4-dicarboxylic acid and ethane-1,2diol

Question 15

Name some uses of terylene (PET)

Answer 15

Used in plastic bottles, clothing, sheets and sails

Question 16

Draw an equation showing how terylene (PET) is formed

Answer 16

Question 17

Hydrolysis

Draw the original monomers

Answer 17

Question 18

Condensation polymers are ______ than addition polymers

Answer 18

stronger & more rigid

Question 19

Why are condensation polymers stronger & more rigid than addition polymers?

Answer 19

• ∵ 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

Question 20

Why are polyalkenes (addition polymers) non-biodegradable and won’t react when being used?

Answer 20

Have non-polar C-C bonds = unreactive and chemically inert

Question 21

Why are condensation polymers biodegradable?

Answer 21

• 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

Question 22

Name 3 ways of disposing waste plastics

Answer 22

• Burying in landfill
• Burning as fuel
• Recycling

Question 23

When are plastics placed in landfills?

Answer 23

When plastic is:

• Difficult to separate from other waste
• Not in sufficient quantities to make separation financially worthwhile
• Too difficult technically to recycle

Question 24

Name an advantage of using landfills to dispose plastics

Answer 24

Landfill is cheap and easy method of waste disposal

Question 25

Name 3 disadvantages of using landfills to dispose plastics

Answer 25

* Requires areas of land * As waste decomposes, can release methane = greenhouse effect * Leaks from landfill contaminate water supplies

Question 26

What is an advantage of burning plastics (excluding its cost and ease)?

Answer 26

Heat can be used to generate electricity

Question 27

Why when burning waste plastics, does the process need to be carefully controlled?

Answer 27

To reduce release of toxic gases e.g. polymers that contain chlorine (PVC) produce HCl when burned = has to be removed

Question 28

Burning Waste Plastics How is the release of toxic gases reduced?

Answer 28

Waste gases from combustion as passed through scrubbers which neutralise gases like HCl by allowing them to react with a base

Question 29

What is a disadvantage of burning waste plastics?

Answer 29

Waste gases e.g. CO₂ will still contributed to greenhouse effect

Question 30

Name 2 ways to recycle plastics

Answer 30

* 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

Question 31

Name 4 advantages of recycling waste plastics

Answer 31

* 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

Question 32

Name 4 disadvantages of recycling waste plastics

Answer 32

* 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

Question 33

Name the molecule

Answer 33

1,4-butanedioic acid