It's National Chemistry WeeK

In honor of National Chemistry Week, (October 16 - 23rd), let's look at the chemistry that makes...

Crayola waxy

It all started with Edwin Binney, and his cousin Harold Smith. They owned a booming school supplies company, which meant that thousands of boxes containing the company’s various products needed to be marked and inventoried using ink labeling markers, which were common at the time, but messy. Not necessarily looking to invent a new product, but more interested in solving an untidy problem, Binney and Smith developed a mess-free marking crayon by mixing carbon black with paraffin wax. To make the marker clean and easy to use they wrapped it in a paper sleeve.

The chemistry of the Crayola is one of the most guarded secrets in the toy industry – for it’s that exact mixture of colorant, talc, and paraffin wax that gives Crayola crayons their color, quality of line and, of course their distinctive aroma.

Silly Putty stretchy

Technically, it is a liquid containing long molecule chains called polymers which can slip and slide over one another and flow like a liquid. But wait! These polymers are linked and if rapid force is applied to them they will become tangled, catch on each other, resist force and act like an elastic solid. This why you can BOUNCE a wad of Silly Putty like a rubber ball. Extremely rapid force will cause the polymers to snag even more and break apart like a solid.

This is why a ball of Silly Putty will settle into a blob if left alone, spring back if bounced and shatter if struck with a hammer. That’s why when it first came out it was called “The Real Solid-Liquid.”

Super Ball bouncy

Chemist Norm Stingley took a synthetic rubber (polybutadiene), mixed it with natural rubber from rubber trees and then compressed it under 2,500 pounds per square inch with explosive results.

“The first ball I made blew up!” he told me. “I compressed it and as soon as I opened the mold this stuff immediately tried to get out and tore itself to pieces! I later got patents on the molding procedure because you had to do it correctly. You have to just barely fill the mold.”

The very first Super Balls would break apart due to the stress of all that bouncing. Over time the chemistry was altered even more by adding vulcanizing agents. These create chemical reactions that causde cross-linking of the polymer chains, increasing strength and resiliency.

Lionel Trains smoky

Realism is the magic behind model railroading and after World War II chemists working at Lionel figured out a way to make locomotives smoke like their real counterparts. Ammonium nitrate pellets were dropped down the engine’s stack and came to rest on a specially made 16–18-volt light bulb (which also doubled as the engine’s headlight). Once the pellet heated up, it liquefied and smoke billowed out with realism. The problem was that ammonium nitrate was found to be unstable. It is essentially a miniature fertilizer bomb! So chemists perfected new pellets that would vaporize with the use of a wire heating element inside of a bulb. Today, a liquid is used.

Nerf Ball spongy

It's a solid, spongy cellular material produced by the reaction of polyester with a diisocyanate while carbon dioxide is liberated by the reaction of a carboxyl with the isocyanate. What? I thought the liberation from polyester was the death of disco or something?

To summarize, polyester resin reacts with a compound while simultaneously a gas (CO2) is released by another reaction. It is this gas that creates these open pockets within the polyurethane which in turn make the material soft and light. Yes, chemistry gave us the Nerf ball.

Now go play with some test tubes!