INDEPENDENCE, Ohio—Make no mistake, Seiichi Kawahara's presentation put the "technical" in the 199th Technical Meeting of the ACS Rubber Division.
But the professor at Nagaoka University of Technology in Japan also provided a pretty simple vision: Creation of a sustainable natural rubber ecosystem to support new industry opportunities is a move that will help clean the environment.
Both natural and synthetic rubber have their place in the market these days.
Kawahara, however, believes development of new approaches can expand both the production and use of natural rubber while also helping the environment through the replacement of synthetic rubbers.
"Natural rubber may have the potential to regenerate a global environment. That is because natural rubber is a resource recycling substance that is biosynthesized by many plants capturing carbon dioxide directly," he said during the meeting's keynote address April 27.
Not only does growing more natural rubber help capture carbon dioxide through photosynthesis, but an increase in such production would lessen CO2 output due to the decreased use of fossil fuel-derived synthetic rubber, the professor said.
Kawahara said this is not only about expanding growth of rubber trees, but also cultivating other sources of natural rubber such as Russian dandelions and guayule that also will help capture more carbon. Researchers have long considered both Russian dandelions and guayule as two promising rubber-producing plants that could help expand natural production.
Natural rubber production is about 13 million metric tons per year, Kawahara said in his presentation. That compares with synthetic rubber production of about 15.5 million tons in 2020, according to an estimate by Mordor Intelligence, a data and research firm.
Hevea brasiliensis trees producing that rubber, primarily in Southeast Asia, absorb about 420 million tons of CO2 per year.
Expanding the development and cultivation of the guayule shrub in arid climates such as the U.S. Southwest and Mexico not only will increase the capture of carbon over time, but also allow for the greening of deserts, Kawahara said.
The professor told attendees of the Technical Meeting via a Zoom call from Japan that he believes a new emphasis on natural rubber production is as a way to mitigate carbon production and global warming can be in place by 2050. The Rubber Division, this year, held the session both with in-person attendees at a suburban Cleveland hotel as well as online due to ongoing COVID-19 concerns.
Much of his presentation delved into technical aspects of bringing along natural rubber production and overcoming obstacles for its use. But the educator and researcher also provided a broad picture of his vision and how increased use of natural rubber can help improve the world.
Part of the work to further natural rubber involves creating processes to make production more efficient. That includes a new way of drying rubber using a heated drum instead of traditional methods of letting it air dry.
This heated-drum approach, where liquid rubber is sprayed on, solidified and then scrapped off, can be accomplished in 45 seconds under conditions already accomplished by research, the professor said. That compares to days for traditional air drying.
"We'd like to establish a natural rubber ecosystem that makes everyone want to cultivate the plants producing natural rubber," Kawahara said. "The reason we have to develop a natural rubber chemistry is, of course, due to a global warming issue. Currently, global warming causes increases in the average temperature, abnormally high temperatures, heat waves, heavy rain and drought. It's a serious impact on the natural ecosystem," Kawahara said.
Global warming, he said, already has impacted biological activities due to the arrival of early spring, and it has impacted water resources and agricultural products.
"In the future, global warming temperatures will have more and more serious considerations for water, food, coastal areas and health," Kawahara said at the Spring Technical Meeting.
To expand the use of natural rubber, the professor said another consideration is the preparation of protein-free natural rubber to help guard against allergic reactions by those sensitive.
Proteins make up about 2.2 percent of natural rubber with rubber hydrocarbon accounting for the vast majority at 93.7 percent. These proteins are not chemically bound, and Kawahara has conducted research into using ammonia, urea and surfactants along with a centrifuge to create protein-free natural rubber.
"We hope to bring about the green revolution by establishing a system of carbon cycles on the surface of earth," Kawahara said, by increasing the growth and output of rubber production vegetation.
He envisions stepping away from human's dependency on synthetic rubbers through the further development of what he calls "a natural rubber chemistry. In other words, I'd like to prepare various products that support human life from natural rubber."
Ultimately he sees the wide use of biodegradable natural rubber products that would release CO2 dioxide into the atmosphere when recycled. That CO2 would then be absorbed by plant life to create a permanent carbon cycle.
