What is Silly Putty?

In 1940 an engineer for general electric, James Wright, was commissioned by the United States War Production Board to find a cheap substitute for rubber.  James Wright accidentally developed Silly Putty, now a famous toy.  Paul Hodgson, a marketer, bought the rights to Silly Putty and started selling it in his local toy store.

Silly Putty is a polymer made from silicone oil and boric acid.  A polymer is a chain of molecules that are all tangled up.  Silly Putty has flexible molecules that, when smooshed by fingers, slide over each other and cause the material to flow.

Silly Putty has been put to many experiments in the past.  Putty is flammable and when lit, the flame is a very bright white.  Though it burns slowly, the left over ash from the putty crumbles very easily.

When putty is microwaved in a drinking glass for about 3 minutes, it becomes very sticky.  However, when cooled the putty returns to the same state it was in before.

When putty is baked at 450 degrees F for 15 minutes, it gives off very bad fumes.  Removed from the oven, the cookie sheet that it was baked on will have a combination of dried putty and very hot, sticky putty.

In 1989 there was the great Silly Putty drop here at Alfred University.  A graduate student decided to do an experiment to settle the question of what would happen to a ball of Silly Putty if dropped from a certain height.  Would the putty bounce, break, or splatter?  An egg of Silly Putty that weighed 100 pounds was dropped from the roof of McMahon Engineering Building.  This drew a crowd all wondering what was going to happen.  When it was dropped, the ball bounced about 8 feet into the air, returned to Earth, and shattered on the second impact.

Purposes of Silly Putty.

Silly Putty has many purposes.  You can bounce it, throw it, decorate with it, stretch it, or make imprints with it.  It can also be used as a stress reliever.  On Apollo 8, the astronauts used it to stabilize their tools in zero gravity.

Composition of Silly Putty.

65% - Dimethyl Siloxane, hydroxy-terminated polymers with boric acid
17% - Silica, quartz crystalline
  9% - Thixotrol ST
  4% - Polydimethylsiloxane
  1% - Decamethyl cyclopentasiloxane
  1% - Glycerine
  1% - Titanium Dioxide

(*Percentages by weight according to

Recipes for Silly Putty.

2 cups Elmers school glue
1 cup liquid laundry starch
Food coloring (optional)

Add starch gradually to glue, mixing with hands.


1.  Add 1/2 cup water to 1/2 cup white glue.
2.  Mix and add 3 drops of food coloring.
3.  Make Borax solution:  take 2 tablespoons Borax, add to 1 cup of water, and stir.
4.  Add 1/2 cup of the Borax solution to water and glue mixture.
5.  Stir and store in a plastic bag.

Web links
This site offers great information about the chemical composition of Silly Putty.
This site is easy to read and has useful information about Silly Putty facts.  This site also has a video on how silly putty is made.  Great for kids to watch.
This site offers fun weird facts about Silly Putty and its uses.  and
These sites both offer good exercises for kids to do.

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