
Mystery Putty - polymerisation
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Joke: What do you get if you
cross a monomer with a monomer? Give up? YOU GET A POLYMER! (I
know; I need to get out more...)
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Chemists don't always make the funniest jokes, but
they can join up a whole bunch of small molecules (monomers) and form
long chains (polymers).
What happens when polymers get tangled up?
You'll find out with PVA and Borax...
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Try this:
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Warning! to teachers and
parents! You may need to lay down some newspaper for this one, it can
get sticky and messy!
RECIPE #1: Mix
one film canister of white glue (add food colour if desired) to one
film canister of water then mix well. Then add one film canister of a
saturated solution of borax. You can pre-mix the glue with equal parts
of water and then add two canisters of the diluted and colored glue
before adding the borax.
RECIPE #2: A
simpler alternative is to pour some white PVA glue into 1/2 a cup of 4%
Borax solution. Slowly stir the PVA into the borax until you
can pick it up with your fingers. Wash the putty in a fresh volume of
Borax until the putty is as firm as you wish.
The result is a bouncing rubber ball! 
You have just carried out a polymerisation
reaction, the idea behind the production of plastics and rayon.
Many small molecules (monomers) join up as
long chains (polymers) that get tangled up to produce a solid substance.
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FIND OUT MORE:-
- Try the rayon
experiment and then find out as much as you can about the production of
plastics.
- Can you find out about injection moulding and
blow moulding?
- Which plastics can be recycled?
- The interactive pages...identify these pieces of lab
equipment
- The interactive pages...weird metals and gases hide
in this Periodic Table
RETURN TO FUN! Science Activities
and Technology Projects