PL 6 - Polymers

Question 1

What are the differences between condensation and addition polymerisation?

Answer 1

Condensation polymers:
- Monomers must have two different functional groups
- Two monomers react, forming a bond between them and releasing a small molecule, usually water
- Can have by-products, usually water or HCl
Addition polymers:
- Monomers can be the same, as long as they have a double bond
- The pi bond breaks and each electron goes to forming a sigma bond with the adjacent monomer
- No by-products; atom economy is 100%

Question 2

What is the relationship between the structural formula of a condensation polymer and that of its monomer(s)?

Answer 2

• A water molecule is released in esterification for every ester formed
• A single repeat unit will have lost the equivalent of 2 water molecules and hence the difference in structural formula between two monomers and a repeat unit is 2 x H2O