Waldo Semon didn’t set out to change the modern world. He just wanted a polymer that stuck to metal.
Born in Demopolis, Alabama, in 1898, Semon was a chemist with a PhD from the University of Washington. By the mid-1920s, he was working for the B.F. Goodrich Company in Akron, Ohio. The industrial landscape was shifting. Rubber was king, but scientists were scrambling for alternatives.
There was a problem with polyvinyl chloride. Known as PVC since 1872, the material was a nightmare to work with. It was incredibly rigid. Brittle. Useless for most applications beyond basic piping, which wasn’t much of a market yet. If you tried to bend it, it snapped. If you tried to mold it, it cracked.
Semon’s goal was simpler. He wanted to create a rubbery substance that could bond effectively to metal surfaces. He was experimenting with high-boiling solvents to dehydrohalogenate PVC. The process was meant to strip away certain elements to soften the plastic.
It worked. Too well.
In 1926, Semon produced a flexible, inert version of the polymer. He hadn’t just made PVC manageable. He had invented plasticized polyvinyl chloride.
The Birth of Koroseal
This wasn’t just a lab curiosity. It was the key to commercial viability.
Before Semon’s discovery, PVC was a scientific oddity. After, it became a commodity. Goodrich trademarked the material as Koroseal. They turned it into shock-absorber seals for vehicles. They used it for electric-wire insulation. They coated cloth with it to make it waterproof and durable.
The shift was massive. Plastic was no longer just a hard, brittle shell. It could be soft. It could be pliable. It could be plastic in the truest sense of the word.
A War-Time Pivot
Semon’s influence didn’t stop at plastic. The 1930s and 40s were a decade of intense material science competition. Natural rubber was scarce. The geopolitical situation in Asia meant supply lines were fragile. The U.S. needed a substitute.
Semon’s technical leadership during World War II resulted in the development of styrene-butadiene rubber (SBR). This synthetic rubber replaced natural rubber in many applications. You can still find it in automobile tires today. It’s the same man who made PVC flexible who also helped build the backbone of the modern automotive supply chain.
Why It Matters Now
We take flexible plastics for granted. We wrap our food in PVC film. We run ethernet cables through our walls. We drive on tires that contain synthetic rubbers developed from wartime necessities.
Semon’s story is a reminder that innovation often looks like a mistake. He was trying to achieve one thing—bonding to metal—and stumbled onto a material that would define the next century of manufacturing.
He died in Hudson, Ohio, in 1999. The plastic remains.
