OCR A Chemistry – Polyesters & Polyamides 6.2.3

What is a TRUE difference between condensation polymers and addition polymers

• addition polymerisation gives off a by-product

• condensation polymers always have amide links

• addition polymer chains are C–C bonds only

• condensation polymers are made from alkenes

Answer explanation

condensation polymers have their chains interrupted by

C–O (ESTER) bonds

or

C–N (AMIDE) bonds

How many DIFFERENT monomers were used to make this polyester?

Tags

NGSS.HS-LS1-6

What atom would be attached to the oxygen on the right hand side of this repeat unit?

• not possible to tell

• H

• O

• C

• N

Tags

NGSS.HS-LS1-6

How many monomers were used to make this polyester? Be careful!

Answer explanation

the repeat unit is made from two monomers

there are n repeat units

made from 2n monomers

Tags

NGSS.HS-LS1-6

Which functional group COULD be used to make this polymer

• acyl chloride

• haloalkane

• aldehyde

• amide

Answer explanation

ACYL CHLORIDE is a "carboxylic acid derivative"

...can be used instead of carboxylic acid!

Which molecule would be unsuitable for making a POLYAMIDE?

• 
• 
• 
• 

Answer explanation

ALCOHOLS are used as monomers ONLY when making polyESTERS.

Any molecule with a carboxylic acid or amine in it would work in making polyamides

TICK THE BEST STATEMENT:

Amino acids are suitable for polymerisation because

• they are chiral

• they can be both acids and bases

• they have both carboxylic acid and amine functionality

• they are found in biology

A polyester is formed from 100 molecules of A and 100 molecules of B.

How many molecules of water are produced?

Answer explanation

use the "total monomers –1" rule to work out the amount of water (condensation by-product).

e.g. 200 monomers – 1 = 199 H₂O

If a polymer forms from 4 mol of identical monomers, how many mol of H₂O are formed

Answer explanation

the number of condensation product molecules is n–1 if the polymer is made from n molecules.

(if the polymer was endless the answer would be n!)

A polyamide is hydrolysed. The products include a positively charged organic molecule.

IN THREE WORDS ONLY, what conditions were used for hydrolysis?

Answer explanation

the organic product contains an ammonium group because the N is protonated by the ACIDIC conditions.