Our Science Saturday project today turned out to be one of
my favorites so far: it was all about polymers.
Actually, this was one of my favorite units when I taught
college chemistry, too. Polymers are awesome. I wanted to come up with some
ideas to make polymers fun for kids.
We began our activity with simple pop
blocks. You know those giant beads that pop together? I let the kids string
beads together like giant trains. As my babies played, I was teaching kids
science.
“Polymer means 'many parts,'” I told them. “Just like the blocks
you’re putting together. Polymers are giant molecules with lots of pieces.”
I turned to Jay. “What kinds of pieces are on a train?”
He thought very seriously for a few seconds. “Well, there
could be boxcars and flatcars and oil tankers and engines and cabooses.”
“Could you make lots of different trains with all those
pieces? Maybe some that have ALL boxcars and some that have oil cars and
flatcars?”
And just like that, our Polymers for Kids lesson took shape.
The kids were envisioning polymers as giant trains with all sorts of different
cars. Meanwhile, they were building long strings of beads to represent
polymers. Some strings were all the same color, and some were rainbow colored.
Once we go the polymer strings built, we moved on to the experiment part. We were actually going to make and play with
some real polymers.
For this part, we just needed cornstarch, water, and food
coloring (which is optional). We mixed together about 2 cups of cornstarch and
1 cup of water. It made a bowl full of a substance that’s neither quite a
liquid nor a solid—but some of both. The polymers that make up the cornstarch
have some very fun properties.
If you jam your fingers into the bowl, it will feel like a
solid wall. That’s because the long polymer strings are too large to move out
of the way quickly. However, if you slowly lower your fingers into the bowl, it
will feel like a thick liquid because the polymer chains shift away from your
fingers.
It was wild. Even hubby and I were playing with our bowl of homemade polymer goo. We made a mess of epic proportions, but because it’s just
cornstarch and water, it cleaned up quickly with a damp paper towel.
