Neoprene foam rubber, in both its open-cell and closed-cell forms, has been utilized in a wide variety of applications for decades. Solid neoprene rubber—though exceptionally useful in its own right—lacks some capabilities that sponge neoprene is known for. In this article, we will detail the history of neoprene foam rubber, answering a few key questions along the way:

• What is neoprene sponge rubber?
• Who invented neoprene foam rubber?
• Is neoprene the same as rubber?
• What is neoprene foam rubber used for?

What Is Neoprene Sponge Rubber?

Neoprene foam rubber is structured by a network of air pockets which gives this type of neoprene many advantages. For example, both open-cell neoprene and closed-cell neoprene sponge have superior absorptive, insulative, and compressive properties than even solid but soft neoprene. The pockets of air contained within neoprene foam rubber physically enable the material to absorb more impact than most other types of rubber. When a force impacts a sheet of neoprene sponge, the energy becomes trapped then rebounds within the structure’s many chambers, dispersing over time due to kinetic energy’s tendency to eventually decelerate. This ability to trap energy also makes neoprene sponge rubber an excellent material for applications requiring insulation. As heat travels through the material’s air pockets, the heat’s speed decrescendos. The air pockets throughout the material retain heat’s energy similarly to how they contain the energy from impacts. Finally, both open- and closed-cell neoprene foam are elastic, which allows them to be compressed easily, permitting them to withstand then rebound from concussive forces without compromising the material’s structural integrity.

Who Invented Neoprene Foam Rubber?

The inventor who pioneered neoprene foam rubber was a scientist named Otto Bayer. Bayer was a chemist working for the German firm IG Farben. In 1937, he discovered—purely by accident—that the introduction of water into a raw, isocyanate-based substance caused vapor to be released within the liquid. These bubbles of vapor could then be trapped as the solution’s transition into a solid form was accelerated. This material, filled throughout with pockets of gas, became the new, sponge-like form of neoprene that we know today as neoprene foam rubber. This new form of neoprene, although fundamentally made of the same material, outshined solid neoprene rubber in many ways. While solid neoprene sheet rubber is irreplaceable in applications such as sealing and gasketing, neoprene foam rubber expanded neoprene’s potential beyond what many had previously thought were its limits.

It should be noted that the idea of neoprene foam rubber was actually proposed as far back as 1930 through the research done by Julius Arthur Nieuwland, a chemistry and botany professor at the University of Notre Dame in Indiana. His chemical research was instrumental in the development of neoprene in its original, elementary form. And while he explored the potential of this novel elastomer, he suggested the possibility of an aerated form of neoprene. His ideas essentially laid the groundwork for the rise of both open-cell neoprene and closed-cell neoprene sponge elastomers. And his prescience about cell neoprene would cement his position in the history of neoprene as a forward-thinker and founding figure.

Eventually, the chemical giant DuPont brought the rights to the material and began developing it. The very first type of neoprene was not exactly the neoprene sponge rubber that we know today. It was rudimentary at best, and it emitted a terrible odor. In fact, this odor was so repulsive that it was the main factor limiting neoprene’s commercial viability. But soon, researchers at DuPont eliminated this problem, and neoprene’s popularity quickly grew. The year 1937 saw the market release of the refined neoprene material that we still use today. It was highly profitable for DuPont. By 1939, the new neoprene elastomer brought in profits of over $300,000 for the company, an amount which had the purchasing power equal to about $6,500,000 today.

Is Neoprene the Same as Rubber?

Neoprene is not the same thing as natural rubber, but it is a type of rubber. While neoprene’s usage was steadily increasing in the 1930s, one event in particular caused neoprene foam rubber’s demand to increase exponentially: World War II. According to the American Chemical Society, by the late 1930s, most of the global supply of natural rubber came from Southeast Asia. Countries such as Thailand and Vietnam held most of the world’s rubber trees after the trees’ continent of origin, South America, in the early 1900s became ruthlessly plagued by the South American leaf blight, a fatal disease targeting rubber trees. During the late 1930s, Japan also began its invasion of Southeast Asia, slowly wresting control over the world’s supply of natural rubber, a shift in industrial power which left Western countries such as the U.S. bereft of affordable rubber. Considering how important rubber already was to society and war in the 1940s, its shortage profoundly affected scientific efforts: industrial foci shifted toward the massive incorporation of a synthetic material which reproduced natural rubber’s properties. By this time, the U.S. was already using neoprene commercially. Though a niche market, shoppers purchased products such as neoprene gloves. But because the American war effort took precedence over its consumer market, all of the U.S.’s neoprene production was expanded then reorganized into the military-industrial complex. Eventually, neoprene supplanted natural rubber as the U.S. military’s main elastomer. Along the way, neoprene sponge rubber found its position within the military’s meticulous network of tools: people discovered that neoprene sponge rubber performed better in certain conditions than did solid neoprene rubber. Ultimately, Japan’s effective barring of the U.S.’s neoprene imports caused neoprene—which includes neoprene sponge rubber—to become a widespread and commonly-recognizable material.

What Is Neoprene Foam Rubber Used For?

Neoprene foam rubber is used for many applications, including aquatic, construction, and automotive applications. Since the time of World War II, the production of solid neoprene rubber sheets and neoprene foam rubber has become a large-scale industry. After World War II ended, neoprene transferred its wartime success into the commercial sphere. As the automobile industry boomed, so did the demand for neoprene. Its excellence in a variety of industrial and commercial applications made it an indispensable part of the modern world. Now, neoprene sponge rubber is used in applications involving marine aquatics, light chemicals, heat insulation, automotive machinery, building construction, and more. Thus, while you differentiate various types of neoprene foam, remember its history: seeing how history has treated this material can illuminate how you, too, might best use it. Although open-cell neoprene and closed-cell neoprene sponge are similar in some respects, they each feature a unique set of properties which orients it toward certain uses. Additionally, neoprene products differ in terms of durometer, material blend, and thickness, changing the product’s ideal application. As neoprene has developed from its inception, it continues its improvements in the present. Neoprene foam rubber is becoming a larger part of many specialized and everyday functions, ensuring its ongoing place in our future as a truly general-purpose elastomer.