Nylon was discovered by an American chemist
called Dr. Carothers, who was trying to make silk.
And silk is a protein.
And he said, "I'm going to put together
molecules to make a protein-like structure."
And he took molecules which were rather--
not quite the same as this.
There are a number of ways of making nylon.
These are the ones I'm going to take to make nylon
and to show you this.
He took molecule with two amino groups on either end,
and this is just a hydrocarbon in the middle,
molecule with two chlorine atoms on either end,
and a molecule with amino groups.
So he took a lot of those and a lot of those, and mixed them.
And when he mixed them, a reaction occurred.
These have combined to form--
these combine to form--
I pulled the wrong one off, haven't I?
I pulled oxygen off.
I'm sorry.
These combine to form hydrogen chloride.
And so these molecules could link up like this.
But you see they're reactive at both ends,
so the other end can do the same thing.
And we can-- and we've got a molecule twice as long.
If I do it again, form another hydrochloride,
and link up again, we have a molecule three times as long.
And so you can go on and on, and get the long threads of nylon.
Let me show you that this actually
does happen spontaneously.
Here I have-- this is the one with the chlorine atoms on,
which is called sebacoyl chloride.
I'll pour that in first, because it's
dissolved in carbon tetrachloride, which is heavy.
And this is dissolving in water.
This is the other one, the hexamethylenediamine,
which I'll pour on the top of this first layer so.
And you can probably see already perhaps a bit
of hydrogen chloride coming off, which we
would expect from what I said.
And you can probably also see some goo has been formed.
Can you see some goo?
Oh yes.
Right, well let's just pull out a bit of that goo like this.
See?
And pull the goo out, some of it, and a bit more.
And now, very shortly, with a bit of luck,
if I can get it from the wall, we shall get a thread of nylon.
And it tend-- the nylon tends to stick to the wall a little bit.
There we go, thread of nylon.
And we can spin some more nylon.
We'll put a little spinneret on it, like that.
Put this over the top of the beaker, like so.
Do a bit more fishing.
Pull the nylon out.
There's a thread.
Put him over the spinneret.
And then I didn't have to work very hard,
if gravity will do it for me.
Let's see whether gravity will do it for me.
There it goes, and it'll go on spinning until it's
used up all the liquid.
And that's nylon thread.
And that has been--
let's let gravity have a bit more chance by raising it--
and that's going spontaneously all the time, you see.
The molecules are combining spontaneously without any help,
because these molecules have enough energy to do so,
and to combine spontaneously.