3.12 Polymers

Question 1

Condensation polymerisation

Answer 1

The reaction between monomers containing two different functional groups with the loss of a small molecule

Question 2

What can polyesters be formed from?

Answer 2

• A dicarboxylic acid / diacyl chloride and a diol
• A monomer with both of these groups

Question 3

Small molecule formed when polyester is formed from a diol and a dicarboxylic acid?

Answer 3

Water

Question 4

Uses of polyesters

Answer 4

• Sportswear
• Carpets

Question 5

What can polyamides be formed from?

Answer 5

• A dicarboxylic acid and a diamine
• A monomer with both of these groups

Question 6

Small molecule formed when polyester is formed from a diol and an acyl chloride?

Answer 6

HCl

Question 7

Uses of nylon

Answer 7

• Clothing
• Rope
• Parachutes
• Carpet

Question 8

Properties of nylon

Answer 8

Strong and resistant to abrasion

Question 9

Uses of kevlar

Answer 9

• Bullet proof clothing
• Flame resistant materials

Question 10

Why is kevlar strong

Answer 10

• Chains are flat and can pack close together
• So stronger intermolecular forces
• Hydrogen bonding between the nitrogen and hydrogen atoms of the amide link

Question 11

Condensation polymers are _______ and _____________ than addition polymers

Answer 11

stronger, more rigid
(because of the intermolecular forces)

Question 12

Intermolecular forces in polyesters

Answer 12

Permanent dipole dipole forces

Question 13

Intermolecular forces in polyamides

Answer 13

Hydrogen bonding

Question 14

Which polymers can be hydrolysed?

Answer 14

Condensation polymers. Addition polymers are chemically inert due to their C-C backbone

Question 15

Catalysts for the hydrolysis of polymers

Answer 15

• Strong aqueous acid
• Strong aqueous base

Question 16

Products of acid hydrolysis of polyesters

Answer 16

Alcohol and carboxylate acid

Question 17

Products of alkaline hydrolysis of polyesters

Answer 17

Alcohol and carboxylate salt

Question 18

Products of acid hydrolysis of polyamides

Answer 18

Ammonium salt and carboxylate acid

Question 19

Products of alkaline hydrolysis of polyamides

Answer 19

Amine and carboxylate salt

Question 20

Why are addition polymers inert?

Answer 20

The strong C-C bonds between repeat units are non-polar, so are not attacked by nucleophiles. This makes addition polymers non-biodegradable

Question 21

Methods for the disposal of polymers

Answer 21

• Burying
• Combustion
• Reusing
• Recycling

Question 22

Advantages and disadvantages of burying polymers

Answer 22

Advantages:
- Relatively cheap
- Easy
Disadvantages:
- Requires land
- Releases toxins into water supplies and methane

Question 23

Advantages and disadvantages of combusting polymers

Answer 23

Advantages:
- Can produce heat energy
Disadvantages:
- Carbon dioxide
- Incomplete combustion (carbon monoxide and C particles)

Question 24

Problems with burning polystyrene

Answer 24

Can form toxic styrene vapour under some conditions

Question 25

Problems with burning chlorinated polymers

Answer 25

Forms acidic HCl gas

Question 26

Advantages and disadvantages of recycling polymers

Answer 26

Advantages: - Saves expensive oil resources and energy from refining - Lower carbon dioxide emissions that burning - Less waste in landfill Disadvantages: - Sorting plastics is expensive - Technically difficult - Cant always remake the original product