AKRON—On one hand, there is guayule, the shrub native to the Sonoran desert that for 100 years has been the focus of efforts to make it a commercially viable source of natural rubber.
On the other, there is the flower variously known as Taraxacum kok-saghyz, Russian dandelion and “Buckeye Gold,” also known to be a rich source of rubber, and with a much wider potential range of cultivation than guayule.
Research scientists and tire manufacturers are heavily involved in the effort to make both guayule and TKS commercially successful, and they discussed their findings at the International Tire Exhibition & Conference in Akron Sept. 9-11.
The case for having alternates to Hevea brasilensis is obvious, according to Katrina Cornish, endowed chair and Ohio research scholar in bio-emergent materials at Ohio State University.
“We need alternative natural rubber sources for biodiversity and easing price volatility,” she said. Having a domestic source of NR also is extremely desirable, she said. But the rubber has to be useful in manufacturing, both in quality and quantity, for any plant commercialization program to succeed, she said.
“You can't just order it. You have to produce it,” said Cornish, a renowned expert in both guayule and TKZ. “You have to inspect it, process it and transport it. Someone is going to have to want to buy this.”
While polymers are officially the same, different polymers have different molecular structures and properties, according to Cornish. Comparing TKS and guayule, TKS rubber is much closer to the structure of Hevea, she said.
“Guayule makes an outstanding thin film polymer,” said Cornish, who during her tenure at the U.S. Department of Agriculture's Agricultural Research Service patented a method of making hypoallergenic latex from guayule. That patent was later assigned to Yulex Corp., where Cornish also worked.
“I'm a big proponent of guayule for medical products,” she said. “You can use guayule even if you have a Type I latex allergy.
“You can actually forget you're wearing a guayule glove, they're so comfortable,” she said.
But although guayule also can be used for tires, TKS—which Cornish and her associates rechristened “Buckeye Gold” during their agricultural research project at the Ohio Agricultural Research and Development Center in Wooster, Ohio—is perfect for tires because of its close resemblance to Hevea, she said.