Happy holidays everyone! This week’s question came from someone on Facebook, who wanted
to know what sodium polyacrylate was doing in there hair gel.
I asked them if they would hold off for the month.
I actually got the question in November, but I asked if they could hold off until now because
the answer is very holiday appropriate, and you’ll find out why, at the end.
Here we go.
So this is a molecules of sodium polyacrylate.
And it has a positive sodium with a negative oxygen and there is a double bonded oxygen
over here, and that is connected to a carbon chain, with these hydrogens hanging off of
it.
So some people will give the definition as a salt or ester of acrylic acid.
They form a polymer which means that these little units that you see, repeat until they
form a loooong chain.
The ingredient was one of many synthetic polymers invented after the 1960’s when the US Department
of Agriculture was looking for a superabsorbent polymer that could hold water in soil.
The first one of those synthetic polymers was called the SUPER SLURPER.
It went down the wrong pipe.
It went down the wrong pipe!
Okay, that sucked.
Literally!
Sodium polyacrylate is in your hair gel because it provides thickness and holding power.
Hair gels are about 80% water, so this ingredient is in there to prevent it from being runny,
and make it more manageable, and give it some substance.
When it’s combined with other ingredients like polyethylene and polyvinylpyrrolidone
it creates a clear film between the hair strands and when it dries, it holds the hair strands
in place
Sodium polyacrylate can be found in diapers, where it has the ability to absorb 200-300x
it’s mass in water.
That is a lot of baby pee.
It can also be found in potting soils and refreezable gel packs.
Here somewhere, one second, looking for it, ah-ha!
Here is sodium polyacrylate in it’s dry form
And here the polymers are curled up really tight, and that’s because there is a positive
sodium ion,and it is attracted to a negative carboxylate.
But when you add water those sodium ions are free to go. . . and they're replaced by the
hydrogens in water.
The hydrogen bonding between the polymer molecule and the water molecule is what allows it to
absorb so much water!
These water molecules, they surround the polymer and cause it to unravel.
As it stretches and it swells, it exposes more sites that attract water.
Because of water’s unique shape it’s capable of associating two polymer chains, so it forms
a bridge.
This bridge doesn’t dissolve and it doesn’t separate, so it forms a bridge.
This bridge doesn’t dissolve, and it doesn’t separate, instead what it does is form this
stiff swollen gel - they call it a hydrogel.
That sort of reminds of me of a superhero like you have Silver Surfer, you have Wolverine,
and you have Hydrogel!
Let’s see this ingredient in action.
I have my handy dandy graduated cylinder.
I have some sodium polyacrylate, this is about 1 gram, and I have about 30 grams of water.
Here we go!
Hmmmmm.
. . . . ohhh!
Go!
Go!Go!Go!
Go!
Happy holidays everyone!
Isn’t this great?!?
You can now have snow anytime of the year!
You can actually buy THIS on amazon.
If you want to try it at home & have a baby, you can get some out of a diaper.
I’ve put some instructions in the description - check there as well.
Hopefully this experiment was a lot of fun for you.
If you want to see more videos like this and learn about your cosmetic ingredients, then
consider subscribing, and lastly, don’t forget to click that notification bell if
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