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

two

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

ester linkage, check picture

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

Draw a generic repeating unit for a polyester

Answer 8

check

Question 9

Which monomers is Terylene made from?

Answer 9

ethylene glycol and terephthalic acid

Question 10

Draw the repeating unit of Terylene

Answer 10

check

Question 11

What is Terylene used for?

Answer 11

As a fibre for making clothes

Question 12

What is the linkage in a polyamide?

Answer 12

peptide linkage, check picture

Question 13

Which molecule is
eliminated when a
polyamide is formed?

Answer 13

H2O

Question 14

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

Answer 14

Diamine and dicarboxylic acid

Question 15

Examples of polyamides?

Answer 15

Nylon, Kevlar

Question 16

Which monomers is Nylon-6,6 made from?

Answer 16

dipic acid and hexamethylene diamine

Question 17

Draw the repeating unit of Nylon-6,6.

Answer 17

check

Question 18

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

Answer 18

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

Question 19

What is Kevlar used for?

Answer 19

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

Question 20

Which monomers is Kevlar made from?

Answer 20

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

Question 21

What is the repeating unit of Kevlar?

Answer 21

check

Question 22

Why is Kevlar so strong?

Answer 22

Rigid chains and close packing of flat aromatic rings

Question 23

What are polypeptides? What is the linkage?

Answer 23

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

Question 24

Draw a dipeptide.

Answer 24

check

Question 25

Draw the repeating unit of a polypeptide.

Answer 25

peptide linkage, check picture

Question 26

Why are poly(alkenes) not biodegradable?

Answer 26

Non-polar C-H and C-C bonds

Question 27

Why is it bad to burn poly(alkenes)?

Answer 27

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

Question 28

Where do most poly(alkenes) end up?

Answer 28

Landfill sites

Question 29

Why can condensation polymers be broken down?

Answer 29

They have polar bonds

Question 30

How are condensation polymers broken down?

Answer 30

Hydrolysis (opposite of condensation)

Question 31

Why does hydrolysis not happen in normal conditions?

Answer 31

Very slow rate in standard conditions

Question 32

What are the four stages needed when recycling polymers?

Answer 32

Collected → sorted → melted → reformed

Question 33

Advantages of recycling polymers?

Answer 33

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

Question 34

Disadvantages of recycling polymers?

Answer 34

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 35

What does “draw the polymer” mean?

Answer 35

Draw with square brackets, n, and trailing bonds

Question 36

Draw with square brackets, n, and trailing bonds

Answer 36

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

Question 37

What is the difference between addition and condensation polymerisation?

Answer 37

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

Question 38

Explain hydrogen bonding between polyamides.

Answer 38

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 39

Why do polyesters not show hydrogen bonding?

Answer 39

All O-H bonds are removed during polymerisation