Waldo Semon
Waldo Lonsbury Semon

September 10, 1898 (1898-09-10)
DiedMay 26, 1999 (1999-05-27) (aged 100)
Nationality (legal)American
Alma materUniversity of Washington (B.S., Ph.D.)
Known forPVC
AwardsCharles Goodyear Medal (1944)
Elliott Cresson Medal (1964)
Scientific career

Waldo Lonsbury Semon (September 10, 1898 – May 26, 1999) was an American inventor born in Demopolis, Alabama.[1] He is credited with inventing methods for making polyvinyl chloride useful.[2]


He was born on September 10, 1898.[3]

He completed his education at the University of Washington, earning degrees in 1920 and 1924. His doctoral degree was among the first in the nation to be awarded in Chemical Engineering.[4]

Semon is best known for plasticizing vinyl, the world's third most used plastic. He is also credited for being the first to commercialise plasticizers for vinyl, which greatly increased their utility, starting with dibutyl phthalate.[5][6] He found the formula for vinyl by mixing a few synthetic polymers, and the result was a substance that was elastic, but wasn't adhesive. Semon worked on methods of improving rubber, and eventually developed a synthetic substitute. On December 11, 1935, he created Koroseal from salt, coke and limestone, a polymer that could be made in any consistency.[7][8] Semon made more than 5,000 other synthetic rubber compounds, achieving success with Ameripol (AMERican POLymer) in 1940 for the B.F. Goodrich company.[9] In all, Semon held 116 patents, and was inducted into the Invention Hall of Fame in 1995 at the age of 97.

While at B.F. Goodrich, Semon reported to Harry L. Fisher and later supervised Benjamin S. Garvey, both of whom also received the Charles Goodyear Medal. He hired Charles S. Schollenberger who received the Melvin Mooney Distinguished Technology Award.

Semon is sometimes credited with inventing bubble gum, but this is inaccurate. He did invent an indigestible synthetic rubber substance that could be used as a bubble gum (and produced exceptionally large bubbles), but the product remained a curiosity and was never sold. Semon graduated from the University of Washington earning a BS in chemistry and a PhD in chemical engineering.

He was awarded the Charles Goodyear Medal in 1944, the Elliott Cresson Medal in 1964, and the Golden Plate Award of the American Academy of Achievement in 1965.[10] After retiring from B.F. Goodrich, he served as a research professor at Kent State University in Kent, Ohio.[11] He died in Hudson, Ohio, on May 26, 1999, at the age of 100.[12]


Waldo Semon Woods Conservation Area, is named in honor of the inventor, for his donation of land to Metro Parks, serving Summit County, Ohio. It is over 100 acres, with a pond where herons, turtles and amphibians are often seen.


  1. ^ "WALDO SEMON (1898-1999)". Inventor of the Week. Massachusetts Institute of Technology. November 1999. Archived from the original on 2003-03-02. Retrieved 2023-06-01.
  2. ^ Elizabeth M. Smith, ed. (1993). A man of ideas : the biography of Dr. Waldo Lonsbury Semon, inventor of plasticized polyvinyl chloride. Cleveland: the Geon Company.
  3. ^ "Waldo Semon | American chemist". Encyclopedia Britannica. Retrieved 2018-01-16.
  4. ^ "Waldo Semon - He Helped Save the World". washington.edu. University of Washington. Retrieved 5 January 2024.
  5. ^ Semon, Waldo L.; Stahl, G. Allan (April 1981). "History of Vinyl Chloride Polymers". Journal of Macromolecular Science: Part A - Chemistry. 15 (6): 1263–1278. doi:10.1080/00222338108066464.
  6. ^ US 1929453, Waldo Semon, "Synthetic rubber-like composition and method of making same", published 1933-10-10, assigned to B.F. Goodrich 
  7. ^ Current Biography 1940, pp 723-24
  8. ^ Brous, S. L.; Semon, W. L. (1935). "Koroseal, a New Plastic. Some Properties and Uses". Rubber Chemistry and Technology. 8 (4): 641–654. doi:10.5254/1.3539480.
  9. ^ Current Biography 1940, p. 724
  10. ^ "Golden Plate Awardees of the American Academy of Achievement". www.achievement.org. American Academy of Achievement.
  11. ^ Kaufman, Michael T. (28 May 1999). "Waldo Semon Dies at 100; Chemist Who Made Vinyl". The New York Times.
  12. ^ Kaufman, Michael T. (1999-05-28). "Waldo Semon Dies at 100; Chemist Who Made Vinyl". The New York Times. ISSN 0362-4331. Retrieved 2018-01-16.