Making Tires "Green"
News You Can Use
Cars may soon be equipped with the world’s first “green” tires made from plant byproducts rather than petroleum or rubber trees—the traditional raw materials used to make tires. This new type of tire would be produced by microbes that convert sugar into an environmentally friendly rubber.
Rubber is an example of a polymer, a chain-like molecule that consists of repeating molecular subunits called monomers. Rubber is also an elastomer, a material that can undergo more elastic deformation than most materials and still return to its previous size. Natural rubber is made from latex, a substance produced by plants, while synthetic rubber is made in a laboratory by combining monomers derived from petroleum.
The natural and synthetic rubber used to make tires are in tight supply, so tire companies and biotechnology firms are teaming up to find other ways of making tires. For example, Goodyear has teamed up with a biotechnology company named Genencor—now part of DuPont—to genetically engineer microbes so they can produce a molecule called BioIsopreneTM from sugar molecules.
BioIsoprene is used as a monomer to form a polymer called polyisoprene. This polymer is chemically equivalent to the polyisoprene polymer derived from petroleum used to make Goodyear tires and produced under the trade name Natsyn.
“The chemical composition of the new product is almost identical to natural rubber,” says David Benko, a research fellow at Goodyear. “The main differences are related to the number of monomer units contained in each polymer and to non-rubber materials such as proteins that are present in natural rubber.”
Goodyear has already produced prototype tires made with BioIsoprene. The new tires are not for sale yet, but when they are, consumers can look forward to a competitive price, Benko says.
- Biomaterials: The Potential for BioIsoprene (Chemical Week)
- BioIsoprene—Making Synthetic Rubber from Renewable Biomass (video from Genencor)