The Chemistry of Silly Putty


Silly Putty is a moldable silicone-based substance, sold chiefly as a toy, with remarkable properties of stretching and bouncing. It stretches like taffy, yet breaks into pieces if pulled too sharply. You can form it into shapes, like Play-Doh or you can roll it into a ball and it bounces! Silly Putty has not effected my life in anyway, other than entertaining me when I’m bored. I chose Silly Putty for my project because every child at some point in their life plays with Silly Putty. The strange substance always was so peculiar to me that I was curious to see how it worked. I picked Silly Putty so I could finally understand what made it behave like it does and how Chemistry was involved in creating it.

Composition of ...

    • Silicon Oil
    • Boric Acid
    • 65%: Dimethyl Siloxane
    • 17%: Silica, quartz crystalline
    • 9%: Thixotrol ST
    • 4%: Polydimethylsiloxane
    • 1%: Decamethyl Cyclopentasiloxane
    • 1%: Glycerine
  • 1%: Titanium

Main Chemicals, Compounds, Components

    • Silicon Oil: Low thermal conductivity (meaning it does not conduct heat) , low toxicity (toxicity is the degree to which something is poisonous.) , thermal stability (does not decompose at high temperatures), it has the ability to repel water, and does not support microbiological growth. The formula name for silicon is R2SiO.
  • Boric Acid: Soluble in boiling water, low toxicity, compound is white or colorless, mild acid. Prepared by reacting borax ( sodium tetraborate decahydrate) with a mineral acid, hydrochloric acid. The formula name for boric acid is H3BO3

Chemistry's Role

    • Silicon itself is naturally occurring and the most abundant element in the Earth’s crust. Silicon Oil however, is man made and created in a lab. Silicon is obtained by the thermal reduction of quarts (SiO2) with carbon. The reaction is conducted at very high temperatures and therefore is commonly carried out where there is abundant inexpensive power.
  • Boric Acid is man made and was created in 1702 by Wilham Homberg who mixed borax and mineral acid with water. Most boric acid is produced by adding a strong acid such as sulfuric acid to a solution of borax and water. The mixture is then cooled until the boric acid crystallizes. However, Boric Acid is also exists naturally in rocks, soil, and plants as forms of the element boron.

Background Research

How is it made?

Silly putty was made by mistake. During the World War Two the united states was trying to create a substitute form of rubber and Silly Putty was created. Silly Putty is made by putting boric acid with silicon oil. When combined the substance turns into a gooey bouncy material.

Where is it made?

Silly Putty has been a popular toy in the world since 1955. In 1977 it became product of Crayola and has been made in those factories everyday. A sigma blade mixer is what Crayola uses to manufacture Silly Putty. Boric Acid and Silicon Oil are placed into the mixing bowl and blended for a half and hour. After this the machine tips the silly putty onto a cart where it is cut and packaged.

How does it work?

Silly Putty has several unique characteristics. It can bounce when dropped, can stretch very far, and can copy newspaper and comic pages when pressed against it.

Silly Putty is a viscoelastic liquid, it acts primarily as a viscous liquid but also has characteristics of an elastic solid. Silly Putty is a polymer that has covalent bonds but hydrogen bonds within the molecules. These hydrogen bonds that make up Silly Putty can be easily broken. When pulled apart this is why the silly putty will tear if enough stress is applied.

Silly Putty is an elastomer. Elastomers spring back to their original shape after being twisted, pulled, or compressed. This is why when torn the Silly Putty is able to form back into one piece.


Brief Explanation of what Silly Putty is

Composition of Silly Putty

How to make homemade Silly Putty

History of Silly Putty

How Silly Putty Works

How Silly Putty was originally created

History of Silly Putty

How Silly Putty works

Silly Putty random facts

How Silly Putty became a toy

More background on Silly Putty

How Silly Putty is made

Information on Boric Acid

Uses, and chemical properties of Boric Acid

Chemical class of Boric Acid

Uses of Silicon Oil

How Silicon Oil is created

Information on Silicon Oil

How Silicon Oil is created

About the Author

Madi Klepps is a junior at Billings Senior High school. She participates in track but her favorite thing to do is play soccer. She maintains a 3.7 GPA and hopes to keep it that way her senior year