Waldo Semon

Waldo Lonsbury Semon (September 10, 1898 – May 26, 1999) was an American chemist and inventor born in Demopolis, Marengo County, Alabama. Working for the B.F. Goodrich Company in Akron, Ohio, he developed methods for plasticizing polyvinyl chloride (PVC), producing a flexible material marketed as Koroseal, and he later helped develop synthetic rubber. He held 116 U.S. patents.[1][2]

Early life and education

Semon was born in Demopolis. Around 1905 his family moved to the Pacific Northwest, where he grew up in Washington and Oregon. He entered the University of Washington in 1916 and earned a bachelor of science in chemistry in 1920 and, in 1923 or 1924 depending on the source, a doctorate that was among the first in chemical engineering in the United States.[1][2]

Work at B.F. Goodrich

Semon joined B.F. Goodrich in Akron, Ohio, in 1926 and was assigned to find a way to bond rubber to metal. In the course of that work he found that heating PVC with certain liquids produced a pliable, durable, waterproof material. Goodrich first put the discovery aside, but in the early 1930s he convinced the company to market it as Koroseal; the Wikipedia article notes that he was the first to commercialize plasticizers for vinyl, starting with dibutyl phthalate.[1][2]

Bubble gum and other myths

Semon is sometimes said to have invented bubble gum. Sources note that this is inaccurate: commercial bubble gum is credited to Walter Diemer in 1928, while Semon created an indigestible synthetic rubber that could blow large bubbles but was never sold.[1][2]

Honors and legacy

He received the American Chemical Society’s Charles Goodyear Medal in 1944, the Franklin Institute’s Elliott Cresson Medal in 1964 and the Golden Plate Award of the American Academy of Achievement in 1965. He retired from Goodrich in 1963 after a 37-year career, taught as a research professor at Kent State University and in 1974 donated 100 acres to Summit Metro Parks, now the Waldo Semon Woods Conservation Area. He entered the National Inventors Hall of Fame in 1995 and died at age 100.[1][2] Semon is among the Alabama-born innovators, along with Mary Anderson and Lonnie Johnson, whose work shaped modern materials and products.

FAQs

Where was Waldo Semon born? In Demopolis, Alabama, on September 10, 1898.

What is Koroseal? The trade name for the plasticized vinyl that Semon helped develop at B.F. Goodrich.

How old was Waldo Semon when he died? He was 100.

Sources

1. Encyclopedia of Alabama: Waldo Semon
2. Wikipedia: Waldo Semon

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 10, 2026Researched and drafted with AI assistanceReport an issue