Scientists Plant Greener Polyurethane
PULLMAN, WA—Loved for their toughness and corrosion resistance, but not so much for their petroleum base, polyurethanes are getting new green roots at Washington State University.
There, researchers are using canola and other plant oils to cook up new plastics.
The resulting products feature a wide degree of flexibility, stiffness and shapes, according to a research announcement.
The team, led by Michael Kessler of the School of Mechanical and Materials Engineering, has published its findings in the journal ACS Applied Materials & Interfaces.
Looking for Alternative
Polyurethane is extremely tough and corrosion- and wear-resistant, but researchers have been looking for alternative production routes for the petroleum-based product, according to the university.
About 14 million tons of polyurethane were produced in 2010, and production is expected to increase by almost 30 percent by 2016.
In this study, the researchers made polyurethane using olive, canola, grape seed, linseed and castor oils.
Plant oils are inexpensive, readily available, renewable and can be genetically engineered.
To make polyurethane, manufacturers combine two types of chemical compounds in a reaction, the research announcement noted.
|Washington State University via phys.org|
Professor Michael Kessler (left) and his team have developed polyurethanes based on plant oils.
One of the chemicals is a polyol, a compound with multiple hydroxyl functional groups that are available for reaction, the university explains.
Some oils, like linseed oil, have five or six reactive sites, resulting in a stiffer material. Others, such as olive oil, have fewer reactive sites, making the material more flexible.
“What’s new about this is specifically the way we make the polyols,” said Kessler. He compared the process to building with Legos. “It is the same concept with these chemical groups. They click together and form a chemical bond.
“The novelty of this particular work is that these polyurethanes are using a new chemistry made by a combination of castor oil fatty acid and modified vegetable oils,” he said.
Kessler hopes the research will appeal to the plastics industry for possible commercialization.
Kessler is the director of the Center for Bioplastics and Biocomposites—the first industry and university cooperative research center devoted to the development of biologically based plastics. It is a collaborative effort between Washington State University and Iowa State University.
The center was made possible by a grant from the National Science Foundation.
More than 20 companies are members of the center.