Silly Putty was first created during World War II by researchers who were trying to develop synthetic alternatives to rubber, an important commodity that was rationed during the war. While more than one researcher claims the initial discovery, Crayola lists James Wright, who worked for General Electric, as the inventor. What Wright (at GE) and another team (at Dow Corning) had separately discovered in their labs was that a combination of boric acid and silicone oil yielded a stretchy substance that bounced when dropped. Despite its unusual (and entertaining) properties, the putty wasn't a viable alternative to rubber. No good use for the putty was found, in fact, until a toy store owner saw it and realized its tactile potential—as a toy. The familiar egg-shaped container came later, along with more than a quarter million units sold in three days, and the rest, as they say, is history, although the putty's path from the lab into popular culture didn't happen overnight. Though Silly Putty didn't enjoy simple rocket-to-the-top success, it did shuttle to the moon with the crew of Apollo 8 in 1968. Today, the putty even has a spot at the Smithsonian Institute.
food coloring
1/2 tsp. Borax powder
3 Tbsp. Cornstarch
4 Tbsp. Warm water
2 cups to mix in
stirring utensils like a spoon or clean popsicle stick
While Silly Putty, from the store, can be a fun and inexpensive diversion for the kids, putty is one of many DIY mediums you can mix at home for a quirky, crafty, scientific experience that's perfect for the family, or in this case, my group of 12 kids. Best of all it gave them something to play with afterwards, but that's another story :)
Substances like Silly Putty are part of a class of materials called polymers. Like other molecules, polymers are compounds, but they are large and may contain tens of thousands of atoms. Compare this, for example, to water, a compound of hydrogen and oxygen that contains three atoms. A good way to visual the difference between small molecules (like water) and polymers (also called macromolecules) is to think of the size difference between a crystal of salt (small) and a strand of spaghetti (larger and longer). Like the strand of spaghetti, polymers are long chains of molecules strung together. These strands can also be tangled up to create a giant mess of polymer chains. Are you still envisioning a bowl of spaghetti? :)
Part of what makes polymers interesting is that each polymer has unique properties and behaviours defined by its molecules. Some polymers are stretchy. Some are sticky. Some are hard. Many familiar and commonly used polymers are synthetic, but there are also naturally occurring polymers, including cellulose, starch, proteins, silk, and rubber. What you want your putty-mixers to understand is that Silly Putty has its characteristic stretch and bounce because of the molecules from which it is made.
Using a combination of Elmer's white school glue, borax (a cleaner made from sodium tetraborate), (most soapmakers know what this is) and water, you can create a substance similar to Silly Putty. The polymer in our 'DIY putty' is not the same as in a commercially sold egg-container of Silly Putty, but glue and borax react to form a similar polymer structure. One of the ingredients in Elmer's glue is polyvinyl acetate—a polymer. When you combine Elmer's glue with borax, a chemical reaction occurs, and borax molecules create links between molecules of polyvinyl acetate in the glue. As more and more cross-linked molecules form, the polymer begins to take on new properties—and new substance. Since you wouldn't pick up and play with a handful of glue, you know that something has happened in the mixing because your putty isn't sticky like glue.
I decided instead of giving them a formulation to follow, to allow them to figure out the optimal ratio of glue to borax themselves. Turned out to be a great science exploration for them. We mixed up separate batches with varying amounts of the two main ingredients, and I invited them to compare the differences in the resulting substances. They felt it, stretched it, and manipulated it with their hands to evaluate the consistency. Is it too sticky? Is it too hard to squish? Does it break too easily?) we continued along until the perfect consistency was achieved.
Part of what makes polymers interesting is that each polymer has unique properties and behaviours defined by its molecules. Some polymers are stretchy. Some are sticky. Some are hard. Many familiar and commonly used polymers are synthetic, but there are also naturally occurring polymers, including cellulose, starch, proteins, silk, and rubber. What you want your putty-mixers to understand is that Silly Putty has its characteristic stretch and bounce because of the molecules from which it is made.
Using a combination of Elmer's white school glue, borax (a cleaner made from sodium tetraborate), (most soapmakers know what this is) and water, you can create a substance similar to Silly Putty. The polymer in our 'DIY putty' is not the same as in a commercially sold egg-container of Silly Putty, but glue and borax react to form a similar polymer structure. One of the ingredients in Elmer's glue is polyvinyl acetate—a polymer. When you combine Elmer's glue with borax, a chemical reaction occurs, and borax molecules create links between molecules of polyvinyl acetate in the glue. As more and more cross-linked molecules form, the polymer begins to take on new properties—and new substance. Since you wouldn't pick up and play with a handful of glue, you know that something has happened in the mixing because your putty isn't sticky like glue.
I decided instead of giving them a formulation to follow, to allow them to figure out the optimal ratio of glue to borax themselves. Turned out to be a great science exploration for them. We mixed up separate batches with varying amounts of the two main ingredients, and I invited them to compare the differences in the resulting substances. They felt it, stretched it, and manipulated it with their hands to evaluate the consistency. Is it too sticky? Is it too hard to squish? Does it break too easily?) we continued along until the perfect consistency was achieved.
This method can be used to make other fun objects, as it can be shaped into almost any imaginable shape. I first showed my kids this after I realized I was buying an almost constant stream of bouncy balls. I got them together and had them make their own bouncy balls which eases mom and dad pockets.
THE RECIPE:
11/2 Tbsp Elmer’s white glueTHE RECIPE:
food coloring
1/2 tsp. Borax powder
3 Tbsp. Cornstarch
4 Tbsp. Warm water
2 cups to mix in
stirring utensils like a spoon or clean popsicle stick
No comments:
Post a Comment