Robert Thomas


William Sparks

Synthetic rubber, lithium-ion battery components, seismic imaging technology… these are just some inventions from ExxonMobil. Read how these pioneers have opened doors to further learning and exploration in their fields and beyond. 

Until the 1930s, much of the world’s rubber was sourced from trees in remote plantations in Asia, West Africa and the tropics of South America. However, as auto production surged, suppliers couldn’t produce enough natural rubber to meet an ever-expanding demand for tires and inner tubes, leading scientists to begin working on creating a synthetic alternative.

In 1937, William Sparks and Robert Thomas, petroleum chemists at the Standard Oil Company of New Jersey laboratory in Linden, N.J., developed one of the most successful synthetic alternatives. Their innovation, called butyl rubber, relied upon a chemical reaction between Vistanex, an adhesive also invented by company scientists, and a small amount of the industrial chemical butadiene.

The new product created a practically impermeable barrier, was flexible while retaining its shape and dampened vibration. These characteristics made butyl rubber excellent for many things, but especially for tires, which needed to hold in air, flex when rolling over bumps, and isolate road vibrations, making for a smoother ride for the passengers in the vehicle. Their invention really took off during World War II, when Standard Oil built and operated the first commercial butyl rubber facility in cooperation with the U.S. government.

Over the years, Standard Oil became ExxonMobil, and the ingenuity of Sparks and Thomas made ExxonMobil the global leader in butyl rubber, a position the company has continually held for nearly 80 years. ExxonMobil is also the global leader in producing the more advanced halobutyl rubber, used to make tire innerliners. A synthetic innerliner keeps your tires inflated for longer and prevents oxygen from entering and degrading the tire.

Halobutyl innerliners also increase fuel economy and lower emissions. Keeping tires properly inflated helps save about 1 billion gallons of fuel and a related emissions reduction of 8 million tonnes CO2 per year. This is equivalent to fuel used by about 2.5 million cars worldwide.

Robert Thomas retired in 1965 after a 46-year ExxonMobil career, in which he earned 75 patents. William Sparks became ExxonMobil’s chief scientist and earned 145 patents before retiring in 1967. Robert Thomas and William Sparks were recently inducted into the National Inventors Hall of Fame, and their story is now on display at the 500-member gallery of icons at the National Inventors Hall of Fame Museum in Alexandria, VA.


Photo credit:

Hero: ExxonMobil Historical Collection, di_03563, The Dolph Briscoe Center for American History, The University of Texas at Austin


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