Polymers

Question 1

When do addition polymers form?

Answer 1

When unsaturated monomors react
The monomers have C=C

Question 2

Give an example of an addition polymer:

Answer 2

Poly(alkenes)

Question 3

What makes poly(alkenes) non-biodegradeable?

Answer 3

Because they are chemically inert due to the strong C-C and C-H bonds and the non-polar nature of the bonds.
The non-polar bonds aren’t susceptible to attack from nucleophiles such as water so cannot be hydrolysed and thus are non-biodegradeable

Question 4

What two linkages are involved in condensation polymers and what are the two most common types of condensation polymers?

Answer 4

Ester linkages and Amide linkages
Polyesters and Polyamides

Question 5

What happens in condensation polymerisation?

Answer 5

Two different monomers that add together and a small molecule is usually given off as a side product e.g. H2O or HCl

Question 6

Give 2 equations to show the formation of a poly(ester)?

Answer 6

dicarboxylic acid + diol –> poly(ester) + water
diacylchloride + diol –> poly(ester) + HCl

Question 7

Give 2 equations to show the formation of a poly(amide)?

Answer 7

dicarboxylic acid + diamine –> poly(amide) + water
diacyl chloride + diamine –> poly(amide) + HCl

Question 8

How are condensation polymers formed? Give three ways:

Answer 8

Dicarboxylic acid + diamine
Dicarboxylic acid + diol
Amino acids

Question 9

What is Kevlar?

Answer 9

A polyamide

Question 10

What two molecules is Kevlar made from?

Answer 10

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

Question 11

What is nylon 6,6?

Answer 11

A polyamide

Question 12

What two molecules form Nylon 6,6?

Answer 12

Hexanedioic acid & 1,6-diaminohexane

Question 13

What are the three types of condensation polymer?

Answer 13

Polyamide, polyester, polypeptide

Question 14

Give two examples of polyamides?

Answer 14

Kevlar + Nylon 6,6

Question 15

What two molecules are needed to make a polyamide?

Answer 15

Dicarboxylic acid, diamine

Question 16

Dicarboxylic acid + diamine –>

Answer 16

polyamide + 2nH20

Question 17

Where do the two molecules of water come from during the formation of a polyamide?

Answer 17

In order to form the repeating unit, one molecule is lost so the amide linkage can form and the other molecule is lost so that the repeating unit can join to other repeating units.

Question 18

What is kevlar used in?

Answer 18

Bulletproof vest, sports equipment, car tyres

Question 19

What is nylon 6,6 used in?

Answer 19

parachute fabric, ropes, clothing, carpets

Question 20

Give an example of a polyester?

Answer 20

Terylene

Question 21

What is terylene used in?

Answer 21

Plastic drinks bottles, sheeting and clothes

Question 22

What is the acronym of terylene?

Answer 22

PET

Question 23

What is terylene made from?

Answer 23

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

Question 24

Why are condensation polymers stronger than addition polymers?

Answer 24

Because of the polar C-N and C=O bonds, hydrogen bonds exist between the polymer chains, as well as dipole-dipole and VDW forces.

Question 25

Why are condensation polymers biodegradeable?

Answer 25

Due to the polar bonds which are susceptible to nucleophilic attack - broken down by hydrolysis slowly Nucleophiles include water

Question 26

Why are addition polymers not biodegradeable?

Answer 26

They are chemically inert, due to their molecules being saturated and them having no polar bonds --> unreactive

Question 27

What is the benefit of using addition polymers in food?

Answer 27

They don't react due to them being chemically inert

Question 28

What type of plastics are disposed of using landfill? Give 3 types:

Answer 28

Ones that are: Too difficult to recycle Too difficult to separate from other materials Not enough plastic to extract to make it economically viable

Question 29

What are the risks of landfill?

Answer 29

Methane released as waste decomposes Water contamination due to waste leaching Not very sustainable Increasingly expensive - land needed

Question 30

When is incineration used?

Answer 30

When plastics cannot be recycled

Question 31

What are the risks with incineration?

Answer 31

Could release toxic fumes e.g. burning chlorine based plastics such as PVC as this release HCl gas

Question 32

What is a benefit to using incineration?

Answer 32

The burning generates energy

Question 33

How can the risks of incineration be combatted?

Answer 33

Using flue gas scrubbers to neutralise the acidic harmful gases (HCl) --> a base is fired at them

Question 34

What are 3 ways of disposing of plastics?

Answer 34

Landfill, incineration, recycling

Question 35

Why is recycling good?

Answer 35

Because most plastics are made from crude oil, crude oil is non-renewable so it reduces the dependency on crude oil.

Question 36

What are the 2 ways of recycling? Explain:

Answer 36

Cracking and remoulding. Some plastics e.g. poly(propene) can be remoulded into new objects Other plastics can be cracked into monomers to be used as organic feedstock for plastics/other substances

Question 37

4 advantages of recycling plastics?

Answer 37

cheaper than making from scratch less CO2 than incinerating them reduces reliance on landfill preserves non-renewable raw materials e.g. crude oil

Question 38

4 disadvantages of recycling plastics?

Answer 38

plastics can be contaminated w/ other materials when being recycled there is a wide variety of different plastics difficult to remake the original plastic sorting + processing plastics to be recycled is ££ compared to incinceration

Question 39

What polymer has hydrogen bonding between the polymer chains?

Answer 39

Kevlar