Organic 12: Polymers

Question 1

Define polymer.

Answer 1

Long chain molecule made from lots of smaller molecules joined together

Question 2

Define monomer.

Answer 2

Small molecules that join together to make polymers

Question 3

What is addition polymerisation?

Answer 3

The formation of long chain molecules from lots of small molecules joining together with no other products

Question 4

What is condensation polymerisation?

Answer 4

The formation of long chain molecules from lots of small molecules joining together with another small molecule (e.g. water) produced as well

Question 5

What monomers are used in addition polymerisation?

Answer 5

Alkenes
(molecules with C=C bonds)

Question 6

Are addition polymers biodegradable and why?

Answer 6

No, because there are no polar bonds in the main chain (all bonds are C-C)

Question 7

Give two examples of addition polymers.

Answer 7

Poly(ethene)
Poly(propene)
Polychloroethene (PVC)

Question 8

What monomers are used in condensation polymerisation?

Answer 8

Dicarboxylic acids + diols
Dicarboxylic acids + diamines
Amino acids

Question 9

Give two examples of condensation polymers.

Answer 9

Polyesters (e.g. terylene)
Polyamides (e.g. nylon, Kevlar)
Polypeptides

Question 10

Are condensation polymers biodegradable and why?

Answer 10

Yes, because there are polar C-N or C-O bonds in the main chain, so they can interact with water (i.e. be hydrolysed)

Question 11

Why are addition polymers chemically inert?

Answer 11

Because all of the molecules are saturated (no double bonds)

Question 12

What are the three ways of disposing of polymers?

Answer 12

Landfill
Incineration
Recycling

Question 13

Describe each of the three ways of disposing of polymers giving advantages and disadvantages.

Answer 13

Landfill:
Burying polymers in the ground

Advantages: cheap, quick, simple
Disadvantages: Stays in the ground for a long time (takes too long to biodegrade), plastic becomes brittle, could break up and be washed away into water sources

Incineration:
Burning polymers

Advantages:
No land pollution
Heat generated can be used for electricity
Disadvantages:
Addition polymers produce CO (toxic) and CO2 (greenhouse gas)
Condensation polymers can also produce toxic gases when incinerated

Recycling:
Collecting, washing, and sorting polymers, then cutting them into small parts to be reused

Advantages:
Not in landfill or being incinerated, so less land pollution and toxic gases
Less energy needed to produce an item from recycled plastics than from new plastics
Disadvantages:
Logistics - relying on the public to recycle, can take a long time to collect it all

Question 14

What type of plastic can’t be recycled?

Answer 14

Thermosetting plastics - they are heated once and they stay in that shape permanently

Question 15

What do diols and dicarboxylic acids look like?

Answer 15

Diols have two hydroxyl (alcohol) groups
Dicarboxylic acids have two COOH groups at either end

Question 16

Where do the condensation reactions happen between a dicarboxylic acid and a diol?

Answer 16

With the OH from the carboxylic acid and the H from the alcohol group

Question 17

What type of polymer forms in a condensation reaction between a dicarboxylic acid and a diol?

Answer 17

Polyester (has repeated ester linkages)

Question 18

What type of polymer forms in a condensation reaction between a carboxylic acid and an amine?

Answer 18

Polyamide (has repeated amide linkages)

Question 19

What two monomers make up nylon 6,6?

Answer 19

1,6diaminohexane
hexane-1,6dicarboxylic acid
(polyamide linkages)

Question 20

What two monomers make up Kevlar?

Answer 20

Benzene-1,4-diamine
Benzene-1,4-dicarboxylic acid
(Polyamide linkages)

Question 21

Why is Kevlar so strong?

Answer 21

Due to the rigid chains and ability of the flat aromatic rings to pack together held by strong intermolecular forces