Section 7 - Polymers

Question 1

What are 3 examples of condensation polymers?

Answer 1

• polyamides
• polyesters
• polypeptides

Question 2

What is a condensation polymer?

Answer 2

Two different types of monomer, each with at least two functional groups, which form a link.

Question 3

Why are condensation polymers called that?

Answer 3

Every time a link is formed, a molecule of water is lost.

Question 4

What do reactions between dicarboxylic acids and diamines make?

Answer 4

Polyamides

Question 5

What is Nylon 6,6 made from?

Answer 5

1,6-diaminohexane and hexadioic acid.

Question 6

What is nylon 6,6 used to make?

Answer 6

• clothing
• carpet
• rope
• airbags
• parachutes

Question 7

What is kevlar made from?

Answer 7

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

Question 8

What is kevlar used to make?

Answer 8

• bulletproof vests
• boat construction
• car tyres
• lightweight sports equipment

Question 9

What do reactions between dicarboxylic acids and diols make?

Answer 9

Polyesters

Question 10

What kind of link is formed in polyesters?

Answer 10

An ester link.

Question 11

What kind of link is formed in polyamides?

Answer 11

Amide link.

Question 12

What is Terylene made from?

Answer 12

benzene-1,4-dicarboxylic acid and ethan-1,2-diol.

Question 13

What is the product of hydrolysis of a condensation polymer?

Answer 13

The original monomers.

Question 14

Why are condensation plolymers stronger and more rigid than addition polymers?

Answer 14

Condensation polymers have polar bonds (they have C-N and C-O bonds). So, as well as VdWs, they have dipole-dipoles and hydrogen bonds.

Question 15

Give a positive and negative of polyalkenes being unreactive and chemically inert.

Answer 15

+ They won’t react with day-to-day chemicals (eg. coffee in a polystyrene cup)

• They are non-biodegradable.

Question 16

What is a positive of condensation polymers having polar bonds?

Answer 16

They are open to attack from nucelophiles and therefore can be broken down by hydrolysis.

Question 17

What are positives and negatives of burying waste plastic?

Answer 17

+ cheap

+ easy

• requires area of land
• decomposing waste can release methane
• leaks from landfill sites can contaminate water supplies

Question 18

When is waste usually buried?

Answer 18

• difficult to separate from other waste
• not sufficient in quantity - separation not financially worthwhile
• too difficult to recycle

Question 19

What is a positive and negative of burning waste plastic?

Answer 19

+ heat used to generate electricity

• leads to the release of toxic gases (eg. PVC releases HCl when burned)
• carbon dioxide release contributes to the greenhouse effect

Question 20

How are waste gases from combustion removed?

Answer 20

Passed through scrubbers which can neutralise gases by reacting them with a base

Question 21

What are two ways to recycle plastics?

Answer 21

• melt and remould
• crack into monomers

Question 22

Give 4 advantages pf recycling:

Answer 22

+ reduces waste going to landfill

+ saves raw materials which are non-renewable

+ cost is lower than making plastics from scratch

+ produces less CO₂ than burning

Question 23

Give 4 disadvantages of recycling?

Answer 23

• technically difficult
• more expensive than burning/landfill
• often can’t make plastic you started with
• plastic can be easily contaminated during process