Polymers: Playing is Learning!
Today students had a really fun chemistry lesson on polymers. The students learned how important polymers are in their 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. Students saw how monomers form chains to create polymers, and that chains of polymers can be cross-linked together to get even different properties. After understanding that polymers are all around us, students were then able to make some polymers of their own.
In three different experiments, students made three unique polymers. Oobleck (corn starch mixed with water) behaves like a liquid when poured, but behaves like a solid when pressure is applied to it. That is because the long polymer (starch) strands in Oobleck slide past each other easily when they are not forced together, but when a pressure is applied, the strands get tangled and the Oobleck acts more like a solid! The second substance, Glubber, was a translucent and sticky, rubbery polymer made with gel glue, water and a cross-link solution (borax dissolved in water). The cross-link solution caused the polymers in the gel glue to bind together and make the glue more solid and stiff. The third substance we made was Globber, which is less sticky than Glubber and is opaque instead of translucent. This was made by mixing Epsom salts with water and gel glue. Globber is a very bouncy polymer that acts almost like rubber!
Just imagine what other unique polymers chemists can come up with. You can see just how fun chemistry can be!