Unit 3: Section 7 - Polymers

Question 1

What is condensation?

Answer 1

Small molecule eliminated (usually H2O) to form a larger molecule

Question 2

How many monomers are condensation polymers usually formed from?

Answer 2

2

Question 3

What properties do the monomers forming condensation polymers have?

Answer 3

Each has 2 functional groups

Question 4

What are 3 examples of condensation polymers?

Answer 4

1. Polyesters
2. Polyamides
3. Polypeptides

Question 5

What are the 2 monomers which form a polyester?

Answer 5

• Diol and carboxylic acid or a molecule with both alcohol and a carboxylic acid functional groups

Question 6

What monomers is Terylene made from?

Answer 6

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

Question 7

What is Terylene used for?

Answer 7

As a fibre for making clothes

Question 8

What are the 2 monomers used to form a polyamide?

Answer 8

Diamine and dicarboxylic acid

Question 9

What are 2 examples of polyamides?

Answer 9

Nylon and Kevlar

Question 10

Which monomers is Nylon-6,6 made from?

Answer 10

1,6-diamineohexane and hexanedioic acid
H2N-(CH2)4-NH2 and HOOC-(CH2)4-COOH

Question 11

If you are making Nylon in the lab, what monomers would you use and why? What molecule is eliminated?

Answer 11

Use hexane-1,6-diacyl chloride as the rate of reaction is must faster
HCl is elimated

Question 12

What is Kevlar used for?

Answer 12

In body armour (bullet proof vests, stab vests), helmets (F1 drivers), oven gloves

Question 13

Which monomers is Kevlar made from?

Answer 13

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

Question 14

Why is Kevlar so strong?

Answer 14

Rigid chains and close packing of flat aromatic rings

Question 15

Why are poly(alkanes) not biodegradable?

Answer 15

Non-polar C-H and C-C bonds

Question 16

Why is it bad to burn poly(alkanes)?

Answer 16

Released CO2, CO, C (soot) and other toxic chemicals from monomers

Question 17

Where do most poly(alkenes) end up?

Answer 17

Landfill sites

Question 18

Why can condesation polymers be broken down?

Answer 18

They have polar bonds

Question 19

How are condensation polymers broken down?

Answer 19

Hydrolysis

Question 20

Why does hydrolysis not happen in normal conditions?

Answer 20

Very slow rate in standard conditions

Question 21

What are the 4 stages needed when recycling polymers?

Answer 21

1. Collected
2. Sorted
3. Melted
4. Reformed

Question 22

What are the advantages of recycling polymers?

Answer 22

• Saves expense of crude oil and preserves a non-renewable resource
• Reduces landfill

Question 23

What are the disadvantages of recycling polymers?

Answer 23

• Energy and manpower is needed for collecting, sorting and melting the polymers, making it expensive
• Can only be done a limited number of times

Question 24

What does draw the polymer mean?

Answer 24

Draw with square brackets, n, and trailing bonds

Question 25

What does draw the repeating unit mean?

Answer 25

Just draw the molecule, with trailing bonds
No brackets or n

Question 26

What is the difference between addition and condensation polymerisation?

Answer 26

• Condensation makes the polymer and eliminates a small molecule
• Addition polymerisation breaks C=C to form only 1 product

Question 27

How do hydrogen bonds arise between polyamides?

Answer 27

1. Both C=O and N-H are polar bonds - N’s electronegativity > H’s and O’s > C’s
2. Hydrogen bonding between Hδ+ and Oδ- in different molecules
3. The lone pair on the O is attracted to the Hδ+

Question 28

Why do polyesters not show hydrogen bonding?

Answer 28

All O-H bonds are removed during polymerisation