Formation of Polyesters Higher Chemistry

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

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)

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.

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.

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

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

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.