Polymers: Playing is Learning!
This week we took a break from circuits and electricity and had a really fun chemistry lesson on polymers. The students learned that they encounter (and even eat!) many different polymers in their everyday lives, since polymers include starches (pasta, potatoes), cellulose (wood, plants), plastics, fabrics both natural (cotton, wool) and manufactured (rayon, nylon), and proteins. But exactly what is a polymer, you might ask? Polymers are a type of molecule made of linked chains of individual units, or monomers. We used paperclips to explore how monomers form chains to create polymers, and how we can change a polymer chain to make a thin, flexible plastic like a grocery bag harder and stiffer like a milk jug.
One way to do this is by cross-linking polymer chains to each other. To demonstrate this concept, the students used a Borax solution to cross-link polymers of white glue together. They were blown away by the instant and dramatic results! As they stirred in the cross-linking solution, the slimy, sticky glue changed into a rubbery, dry substance that they could stretch, form into a ball, break apart, and even bounce! Of course their favorite part was being able to put their “Glubber” in a baggie and take it home to share with everyone!