1. Formation of
Polyesters
Higher Chemistry

2. Our Plan For Today
We are going to learn about condensation polymerisation and the formation of polyesters.
Recap – carbon compounds so far
Two types of polyester
What the structures look like
Appendix Task 2.18

3. Task: circle and name the functional group in each of the following and state what type of compound it is e.g ketone / alcohol. 1) 2) 3) 5) 4) 7) 6)

4. The Two Types of Polyester
Linear
Cross Linked
Fibres are spun together to make strong, flexible products . Used in the clothing industry.
The acids used to make polyester resins are unsaturated so cross linking produces a network structure.

5. Work Booklet Tasks
Look at the information on pages 8 and 9 about polyesters.
Answer the bullet pointed questions on page 9 of your work booklets.

6. Polyester Structure – Starting Materials
Polyesters are formed when diacids and dialcohols react together. O O
HO OH
HO – C C - OH
A diacid has two carboxyl acid groups at either end of the molecule.
A dialcohol has two hydroxyl groups at either end of the molecule.
Represent different arrangements of carbon and hydrogen atoms.
and

7. Condensation Polymerisation
The acid and alcohol groups react together with the loss of water. O O O O
HO – C C -OH
HO – -OH
HO – C C -OH
HO – -OH
Water is removed – condensation polymerisation O O O O O O O O
HO – C C -
O – -O
– C C -
O – -O
– C C -
O – -O
– C C -OH
Ester link
Many ester molecules joined together - polyester

8. Appendix and Activities
Stick a copy of appendix 2.18 into your jotters.
Try activity 2.28.
Use the molymod kits and blocks to try making a polyester.