Synthetic Rubber
Chemical company DuPont begins mass-production of the first commercially available synthetic rubber, Duprene (later named neoprene) in 1932. Because it was difficult and expensive to manufacture, the company turned its attention to developing a synthetic "superpolymer," ultimately leading to the development of nylon.
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In 1930 Wallace Carothers had been asked by Elmer Bolton, the new head of DuPont’s chemical department, to look into polymers based on acetylene. Unlike Stine, who emphasized pure science, Bolton believed that research should be aimed at clearly defined applications. The freewheeling days of fundamental research at DuPont were fading.
Bolton, who previously had headed DuPont’s research on dyes, had long been interested in producing a synthetic rubber. In the late 1920s he had followed the research of Father Julius Nieuwland of Notre Dame University, who used a cuprous chloride catalyst to combine two or three acetylenes into mono- or divinylactetylene. Bolton realized that these compounds were similar to isoprene, the molecule that is the basic structural unit of natural rubber.
Carothers assigned Arnold Collins to make a very pure sample of divinylacetylene. While distilling the products of the acetylene reaction in March 1930, Collins obtained a small amount of an unknown liquid, which he put aside in stoppered test tubes. A few days later he found that the liquid had congealed into a clear homogenous mass. When Collins dislodged the mass from its container, it bounced. Analysis showed that the mass was a polymer of chloroprene, formed with chlorine from the cuprous chloride catalyst. Accidentally, Collins had prepared a new synthetic rubber.
DuPont began large-scale production of polychloroprene, marketed under the name Duprene (later changed to neoprene), in 1932. Neoprene was difficult and expensive to manufacture, however, and it didn’t really rival natural rubber, which was selling for only a few cents per pound in the early 1930s. Neoprene — which was resistant to weather, oil, chemicals, and heat — found several relatively small but profitable uses.
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Excerpted with permission, National Historic Chemical Landmarks Program
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