Polymers

Question 1

Condensation reactions are formed by reactions between:

Answer 1

• dicarboxylic acids and diols (polyesters)
• dicarboxylic acids and diamines (polyamides)
• amino acids (polypeptides)

Question 2

3 main types of condensation polymers

Answer 2

• polypeptides
• polyamides
• polyesters

Question 3

Condensation polymerisation is where

Answer 3

2 different monomers with at least 2 functional groups react together
-> when they react a link is made and water is eliminated (hence condensation)

Question 4

What does the link formed determine

Answer 4

The type of polymer produced

Question 6

What links are formed in polyamides

Answer 6

Amide links

Question 7

Why does we have to use dicarboxylic acids and diamines or diols

Answer 7

Because they have to have functional groups either side which allows for chains to be formed

Question 8

What is kevlar

Answer 8

A polyamides used in bulletproof vests, car tyres and some sports equipment

Question 9

What is kevlar made from

Answer 9

Benzene-1,4-dicarboxylic acid AND 1,4-diaminobenzene

Question 10

What is nylon 6,6

Answer 10

A polyamide that is used in ropes, carpets, clothing and parachute fabric

Question 11

What is Nylon 6,6 made from

Answer 11

Hexanedioic acid AND 1,6-diaminohexane

Question 12

What links are formed in polyesters

Answer 12

Ester links

Question 13

What is a diol

Answer 13

A molecule with 2 alcohol groups

Question 14

What is terylene

Answer 14

A polyesters used in plastic drinks bottles and clothes

Question 15

What is terylene made from

Answer 15

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

Question 16

Condensation can be..

Answer 16

Hydrolysed to produce the original monomers

-> it’s jsut the reverse of polymerisation

Question 17

What kind of bonds do condensation polymers have

Answer 17

Polar bonds

Question 18

Why do condensation polymers have polar bonds

Answer 18

Becuase of the C-O and C-N bonds that exist in polymers

Question 19

Condensation polymers are usually more..

Answer 19

Rigid and stronger than addition polymers

Question 20

What bonds exist between condensation polymers chains

Answer 20

Hydrogen bonds
Dipole-dipole bonds
VDWs forces

-> making them stronger than addition polymers

Question 21

Why can condensation polymers break down more readily in water

Answer 21

They have hydrogen bonds and so can dissolve

Question 22

What are synthetic polymers made from and used to make

Answer 22

Monomer units

Plastic bottles, digital technology and non stick coatings on pans

Question 23

Condensation polymers are..

Answer 23

Biodegradable

Question 24

Why are condensation polymers biodegradable

Answer 24

They are polar and so susceptible to attack from nucleophiles

-> they are broken down by hydrolysis slowly

Question 25

What are polyalkenes

Answer 25

Addition polymers -> they are saturated molecules

Question 26

Properties of polyalkenes

Answer 26

• saturated molecules • non-polar so unreactive • good in foods as they don’t react • don’t degrade well in landfill

Question 27

What does polyalkenes not being polar mean

Answer 27

They are unreactive

Question 28

Landfill is useful for disposing plastics that:

Answer 28

• are too difficult to recycle • are too difficult to separate from other materials • there’s not enough plastic to extract to make it economically viable

Question 29

When waste decomposes in landfill..

Answer 29

It produces methane which is a greenhouse gas • there’s also a risk of water contamination from leaching

Question 30

What’s wrong with landfill

Answer 30

- not sustainable as large amounts of land is needed - expensive to use land - there’s a need to reduce our reliance on landfill

Question 31

What is incineration

Answer 31

Burning waste plastics -> used if the plastics can’t be recycled

Question 32

Why is incineration good

Answer 32

It can be used to generate electricity

Question 33

Why is incineration bad

Answer 33

Burning plastics can release toxic fumes -> especially chlorine based products like PVC which produce harmful HCl gases when burned

Question 34

What is used to balance the release of harmful gas in incineration

Answer 34

Flue gas scrubbers

Question 35

What do flue gas scrubbers do

Answer 35

Neutralise acidic gases produced like HCl

Question 36

How do flue gas scrubbers work

Answer 36

-> they work by firing a base at the flue gases

Question 37

Ways of disposing plastics

Answer 37

• landfill • incineration • recycling

Question 38

Most polymers are made from..

Answer 38

Crude oil which is non renewable

Question 39

Recycling means reducing..

Answer 39

Dependency on crude oil for making plastics

Question 40

Some plastics can be..

Answer 40

Remoulded into new objects Like polypropene

Question 41

Ways plastics can be recycled

Answer 41

• remoulded into new objects • cracked into monomers to be used as an organic feedstock for plastics or other substances

Question 42

Advantages of recycling plastics

Answer 42

- Cheaper than making them from scratch - Less carbon dioxide is produced recycling plastics than incinerating - Recycling reduces the reliance on landfill - Recycling preserves non-renewable raw materials such as crude oil

Question 43

Disadvantages of recycling plastics

Answer 43

- Plastics can be contaminated with other materials - It’s difficult to recycle plastics due to the wide variety of different plastics - It’s difficult to re-make the original plastic from recycled material - Sorting and processing plastics to be recycled is expensive compared with incineration

Question 44

What kind of links to polypeptides have

Answer 44

Amide links (peptide)

Question 45

Why are addition polymers nonpolar

Answer 45

They only consist of C-C and C-H bonds -> rely on weaker induced dipole-dipole forces between chains

Question 46

The presence of stronger intermolecular forces makes condensation polymers:

Answer 46

• More rigid and less flexible • Stronger, with higher melting and boiling points compared to addition polymers

Question 47

Monomers used in addition polymerisation

Answer 47

Alkenes

Question 48

Monomers used in condensation polymerisation

Answer 48

Carboxylic acids, acyl chlorides, amines, alcohols, amino acids

Question 49

Polymer chain in addition polymerisation

Answer 49

Continuous chain of carbon atoms

Question 50

Polymer chain in condensation polymerisation

Answer 50

Constrains ester or amide bonds

Question 51

Products formed in addition polymerisation

Answer 51

Polymer only

Question 52

Products formed in condensation polymerisation

Answer 52

Polymer and small molecule (like water)

Question 53

2 main approaches to recycling waste plastics

Answer 53

Mechanical recycling Feedstock recycling

Question 54

Mechanical recycling

Answer 54

Involves sorting, cleaning and remoulding waste plastics into new objects without significant altering the chemical structure of the polymer

Question 55

Feedstock recycling

Answer 55

Breaks down polymers into their constituent monomers through cracking -> these monomers can then be used as raw materials for the synthesis of new plastics and other organic chemicals