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 these monomers forming condensation polymers have?

Answer 3

Each has two functional groups

Question 4

Examples of condensation polymers?

Answer 4

Polyesters
Polyamides
Polypeptides

Question 5

What is the linkage in a polyester?

Answer 5

R-C=O
l
O-R’

Question 6

What molecule is eliminated in formation of a polyester?

Answer 6

H2O

Question 7

What are the two monomers which form a polyester (generic names and structures)?

Answer 7

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

Question 8

Which monomers is Terylene made from?

Answer 8

Benzene-1,4-dicarboxylic acid

Ethane-1,2-diol

Question 9

What is Terylene used for?

Answer 9

As a fibre for making clothes

Question 10

What is the linkage in a polyamide?

Answer 10

O H
ll l
-C-N-

Question 11

Which molecule is eliminated when a polyamide is formed?

Answer 11

H2O

Question 12

What are the two monomers used to form a polyamide (generic names and structures)?

Answer 12

Diamine and dicarboxylic acid

Question 13

Examples of polyamides?

Answer 13

Nylon, Kevlar

Question 14

Which monomers is Nylon-6,6 made from?

Answer 14

1,6-diaminohexane

Hexanedioic acid

Question 15

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

Answer 15

Use hexane-1,6-diacyl chloride as the rate of reaction is much faster. HCl is eliminated

Question 16

What is Kevlar used for?

Answer 16

In body armour (bullet proof vests, stab vests), helmets (e.g. F1 drivers’), oven gloves

Question 17

Which monomers is Kevlar made from?

Answer 17

1,4-diaminobenzene

benzene-1,4-dicarboxylic acid

Question 18

Why is Kevlar so strong?

Answer 18

Rigid chains and close packing of flat aromatic rings

Question 19

What are polypeptides? What is the linkage?

Answer 19

Same linkage as polyamides. But made from just one amino acid monomer

Question 20

Why are poly(alkenes) not biodegradable?

Answer 20

Non-polar C-H and C-C bonds

Question 21

Why is it bad to burn poly(alkenes)?

Answer 21

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

Question 22

Where do most poly(alkenes) end up?

Answer 22

Landfill sites

Question 23

Why can condensation polymers be broken down?

Answer 23

They have polar bonds

Question 24

How are condensation polymers broken down?

Answer 24

Hydrolysis (opposite of condensation)

Question 25

Why does hydrolysis not happen in normal conditions?

Answer 25

Very slow rate in standard conditions

Question 26

What are the four stages needed when recycling | polymers?

Answer 26

Collected → sorted → melted → reformed

Question 27

Advantages of recycling polymers?

Answer 27

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

Question 28

Disadvantages of recycling polymers?

Answer 28

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 29

What does “draw the polymer” mean?

Answer 29

Draw with square brackets, n, and trailing bonds

Question 30

What does “draw the repeating unit” mean?

Answer 30

Just draw the molecule, with trailing bonds - no | brackets or n

Question 31

What is the difference between addition and | condensation polymerisation?

Answer 31

Condensation makes the polymer and eliminates a small molecule addition polymerisation breaks C=C to form only 1 product (just the polymer).

Question 32

Explain hydrogen bonding between polyamides.

Answer 32

Both C=O and N-H are polar bonds, as N’s electronegativity > H’s and O’s electronegativity > C’s. Hydrogen bonding between H + and O - in different molecules Uses the lone pair of electrons on the O atom

Question 33

Why do polyesters not show hydrogen bonding?

Answer 33

All O-H bonds are removed during polymerisation