1f Designer Polymers
Chemists design polymers to suit the job they have to perform
1. Polythene – correct chemical name is poly(ethene)
Polythene is used to make _______________ and _____________________.
What properties must polythene have to make it a good material for making these?
Polystyrene is used to make the packaging for hot drinks and food
Suggest what properties make polystyrene fit for this purpose
3. Polyester in clothing
Polyester is used to make clothes. It is fairly strong, lightweight and can
be coloured easily
4. PTFE – poly(tetrafluoroethene)
PTFE is used as a non-stick coating for frying pans and saucepans. It has a very
slippery surface that nothing can stick to. It must be:
5. Comparing Gore-Tex® and Nylon
Look at the picture of the climber and think about the properties that his jacket and
trousers must have? Then look at the table and decide whether it would be better to
make them from nylon or Gore-Tex®. You must learn this table of properties
hard wearing hard wearing
keeps out UV light keeps out UV light
not breathable breathable
What do we mean by a material being breathable?
Why is Gore-Tex® breathable
The PTFE layer has tiny _______
that are too ________ for water
to get in but large enough for
_________________to pass out
The PTFE membrane is not very
__________ so it is bonded to a
sheet of ________ to strengthen
In an exam, you must be able to:
1. List the advantages and disadvantages of using Nylon for making outdoor clothes.
Be specific and mention the properties in the table above
2. Explain why Gore-Tex® is better than nylon
3. HIGHER – explain how nylon works
Higher How do the covalent bonds and intermolecular forces affect the
properties of polymers?
The atoms in plastics are held together by strong covalent bonds.
We can explain the properties of plastics by thinking about their structures:
1. Plastics that have weak intermolecular forces between polymer molecules
have low melting points and can be stretched easily as the polymer
molecules can slide over one another
e.g. If your shopping is too
heavy the plastic bag might
stretch – particularly on a very
Easy to break
so mpt is low
2. Plastics that have strong forces between the polymer molecules (covalent
bonds or cross-linking bridges) have high melting points, cannot be
stretched and are rigid.
e.g. UPVC window frames.
Window frames must be rigid.
linking bridges If they were flexible the glass
need a lot of may fall out.
energy to break
to mpts are high
Disposing of Plastics
• Plastics are made from __________________.
• It is difficult to dispose of polymers be cause most polymers are
• Non-biodegradable means that they will not _____________ (rot) or decompose
by bacterial action.
• Because they do not rot away it leads to problems with _________________
3 ways that we can dispose of polymers:
The disadvantage of this method of
Land fill sites 1. Landfill sites get filled quickly wasting
2. Waste of a valuable resource
Burning of waste polymers 1. Burning waste plastics makes toxic gases
CO2 – contributes to global warming
dioxins - any compounds containing Cl, C, H, O
they are toxic e.g. CO
2. Waste of a valuable resource
Recycling You cannot mix different types of
polymers together when they are recycled.
It is difficult to sort out all of the