Like HowStuffWorks on Facebook!

How SuperBalls Work

        Culture | Fads

Science of SuperBalls

Ask any well-stocked lab to give you a small sample of Zectron, and you'd get nothing in return but a blank stare. Possibly a chuckle. That's because it doesn't exist. Norman Stingley coined the term to describe the synthetic rubber he invented on behalf of Wham-O. If you were to identify a real substance behind the Zectron façade, it would be polybutadiene, the main ingredient of a SuperBall. Now you can appreciate why Stingley devised the Zectron moniker. He feared no one would want to buy a ball with "made with amazing polybutadiene" printed on its side.

He might have been right, but the real science behind Zectron is at least a little interesting. Take the name polybutadiene, for instance. It's made up of three distinct parts that provide clues about the material's chemical nature:

  • "-but-" means a four-carbon chain
  • "-ene" means double bond
  • "di-" means two

Butadiene, then, describes a compound built with a four-carbon chain containing two double bonds. A chemist would write this structure as CH₂=CHCH=CH₂, where the parallel lines indicate the double bonds. The final part of the name -- the prefix "poly-" -- tells you that there are many butadiene molecules strung together to form what chemists call a polymer. The polymerization process begins when an unpaired electron on one butadiene subunit steals an electron from an adjacent butadiene subunit, bonding the two together. This sequence of events occurs repeatedly until a long chain of molecules forms.

By itself, polybutadiene doesn't produce an effective material. It becomes gooey at high temperatures and brittle at low temperatures. To transform it into a resilient, stable rubber, Stingley borrowed a page from the lab manual of Charles Goodyear, who discovered that sulfur added to rubber made it flexible and resilient at any temperature. Goodyear called this vulcanization, and Stingley needed to vulcanize his new material, too. He mixed 100 parts by weight of polybutadiene with 0.5 to 15 parts by weight of sulfur. Then he placed the mixture in a mold and cooked it at 285 to 340 degrees Fahrenheit (140.56 to 171.11 degrees Celsius) while simultaneously compressing it at a pressure of 500 to 3,000 pounds per square inch.

The result was the one, the only, the Original SuperBall -- the amazing toy that still delights anyone interested in bouncing off the wall.


More to Explore