1. What does “condensation” mean?

2. Condensation polymers
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Condensation polymers
Formed from condensation reactions between monomers.
A small molecule (often water or HCl) is produced as well as the polymer.
Many natural polymers are condensation polymers, e.g. silk, starch and DNA.
The are three types of condensation polymers; polyesters, polyamides and polypeptides.

3. Condensation Polymers
Normally made from two different monomers – each of which has two functional groups
Each functional group can react, so a long-chain polymer results

4. A2453
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1. Polyesters
Esters are formed on reaction between carboxylic acids and alcohols.
Polyesters are formed when dicarboxylic acids react with diols.
Polyesters are hydrolysed (in the presence of strong acid or a specific enzyme) into their constituent acid and alcohol, so they are bio-degradable .

5. Polyesters Create an ester link –COO- Use diols (two –OH groups)
Use dicarboxylic acids (two –COOH groups)

6. Making a polyester (general)

7. strong acid or specific enzyme
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Polyesters
strong acid or specific enzyme
- H2O

8. MWB
Can you draw the fibre Terylene? (Made from benzene-1,4-dicarboxylic acid and ethane-1,2-diol).

9. strong acid or specific enzyme
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Polyesters
strong acid or specific enzyme

10. Polyester Exam Question

11. A2453
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2. Polyamides
Amides are formed on reaction between carboxylic acids and amines.
Polyamides are formed when dicarboxylic acids react with diamines.
Polyamides are hydrolysed (in the presence of strong acid or a specific enzyme), so they are bio-degradable. .

12. Polyamides Create an amide link –CONH-
Uses diaminoalkanes (has two amine groups)
Uses dicarboxylic acids (has two carboxylic acid groups)

13. Making polyamides (General)

14. Nylon
Nylon-6,6 is made from 1-6-diaminohexane and hexane-1,6-dicarboxylic acid:
What are the structures of these molecules?

15. Nylon

16. A2453
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Polyamides
The reaction will go faster if a diacid chloride is used rather than the dicarboxylic acid.
This would mean HCl would be eliminated
strong acid or specific enzyme

17. A2453
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Polyamides
Kevlar

18. Think
Think about the structures of Nylon and Kevlar. Do you think they will have similar or different properties? Explain.

19. strong acid or specific enzyme
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Polyamides
strong acid or specific enzyme

20. Polyamide Exam Question

21. Where are the links broken?
Can you work out the monomers of these polymers?

22. Forces between condensation polymers
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Forces between condensation polymers
Generally more rigid and stronger than addition polymers
Condensation polymers contain polar bonds (C-N and C-O bonds in the chains)
So as well as VdW forces, there are:
Permanent dipole-dipole forces
Hydrogen bonds
Draw some molecules and show examples of these forces