Glorious Goo and Polymers Too!

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.

If you're looking for a simple activity that is wildly fun, super easy, and incredibly cheap, this is your pay dirt. And from the looks on my babies’ faces when they stuck their fingers into a bowl of crazy goop, they feel the same way.