polymers [O2] PAPER 2

Question 1

Explain why polyesters are biodegradable but polyalkenes are not biodegradable.

Answer 1

• polyesters have polar bonds, but polyalkenes have non-polar bonds
• polyesters are susceptible to nucleophilic attack

Question 2

Answer 2

kevlar

Question 3

how are condensation polymers formed?

Answer 3

a water molecule is removed from the species of the reaction

Question 4

condensation reaction between a dicarboxylic acid and diamine to form a polyamide?

Answer 4

red box = amide linkage

Question 5

example of a polyamide?

Answer 5

nylon-6,6 and kevlar

Question 6

condensation reaction between a dicarboxylic acid and diol to form a polyester?

Answer 6

red = ester linkage

Question 7

example of a polyester?

Answer 7

terylene (PET)

Question 8

condensation reaction between amino acids to form polypeptides?

Answer 8

Question 9

a condensation polymer can be broken down by _____ by the addition of _____

Answer 9

hydrolysis
water

Question 10

Answer 10

A

Question 11

Answer 11

C

Question 12

Two plastic objects were manufactured, one from a polyalkene the other from a polyamide.
After use, it was suggested that both objects be disposed of as landfill.
Describe an experiment in which you could compare the biodegradability of these two objects.

Answer 12

• heat with NaOH
• with polyalkene, no reaction
• polyamide is hydrolysed to form an acid salt and alcohol

Question 13

Describe an advantage or a disadvantage of a different method of disposal of such objects compared with landfill.

Answer 13

• combustion
• heat energy produced
• toxic gases produced