6.2.3- Polyesters & Polyamides Flashcards
What is condensation?
Small molecule eliminated (usually H2O) to form a larger molecule
How many monomers are condensation polymers usually formed from?
Two
What properties do these monomers forming condensation polymers have?
Each has two functional groups
Examples of condensation polymers?
- Polyesters
- Polyamides
- Polypeptides
What is the linkage in a polyester?
Ester linkage: RCOOR’
What molecule is eliminated in formation of a polyester?
H2O
What are the two monomers which form a polyester?
Diol and dicarboxylic acid or a molecule with both alcohol and a carboxylic acid functional groups
What monomers is Terylene made from?
- Benzene-1,4-dicarboxylic acid
-Ethane-1,2-diol
What is Terylene used for?
As a fibre for making clothes
What is the linkage in a polyamide?
Peptide linkage: CONH
Which molecule is eliminated when a polyamide is formed?
H2O
What are two monomers used to form a polyamide?
Diamine and dicarboxylic acid
Examples of polyamides?
Nylon, Kevlar
Which monomers is Nylon-6,6 made from?
- 1,6-diaminohexane
- Hexanedioic acid
If you are making Nylon in the lab, what monomers would you use and why? What molecule is eliminated?
Use hexane-1,6-diacyl chloride as the rate of reaction is much faster. HCl is eliminated.
What is Kevlar used for?
In body armour (bullet proof vests, stab vests), helmets (F1 drivers), oven gloves
Which monomers make up Kevlar?
- 1,4-diaminobenzene
- Benzene-1,4-dicarboxylic acid
Why are poly(alkenes) not biodegradable?
Non-polar C-H and C-C bonds
Why is it bad to burn poly(alkenes)?
Releases CO2, CO, C (soot) and other toxic chemicals from monomers
Where do most poly(alkenes) end up?
Landfill sites
Why can condensation polymers be broken down?
They have polar bonds
How are condensation polymers broken down?
Hydrolysis
What s the difference between addition and condensation polymerisation?
Condensation makes the polymer and eliminates small molecule; addition polymerisation breaks C=C to form only one one product (just the polymer).
Explain hydrogen bonding between polyamides
-Both C=O and N-H are polar bonds, as N’s electronegativity > H’s and O’s electronegativity > C’s
- Hydrogen bonding between H+ and O- in different molecules
- Uses the lone pair of electrons on the O atom
Why do polyesters not show hydrogen bonding?
All O-H bonds are removed during polymerisation
