State team is using
nanoclays to improve plastics made from corn and soy proteins.
Above: Grewell displays plastics developed by a team of Iowa State
The researchers are using nanoclays to improve biorenewable and biodegradable
plastics made from corn and soy proteins. Photo by Bob Elbert/Iowa State University.
David Grewell, an assistant professor of agricultural and
biosystems engineering at Iowa
is working with a team of fellow researchers to reinforce biorenewable,
biodegradable plastics with nanoclays (pieces of clay that are just 10 to 20
billionths of a meter thick). These plastics are produced when glycerin, a
byproduct of biodiesel production, and water are added to a soy or corn
protein. The glycerin acts to lengthen and straighten the compact protein
molecule, but the resulting plastics lack strength.
Nanoclays have been successfully added to petrochemical
polymers to enhance factors like strength and vapor barrier properties, and
Grewell's group is investigating if similar results can be seen in
protein-based polymers. The research team is using surface-treated clays to
enhance mixing and have already seen evidence that vapor barrier properties can
easy to work with those tiny pieces of clay. They tend to stick together in
clumps because of electrostatic forces," said Michael Kessler, an Iowa State
assistant professor of materials science and engineering who's also working on
the project. "Those clay platelets need to be separated and mixed evenly
throughout the plastic to be much good as a reinforcing agent."
The researchers are turning to high-powered ultrasonics-high-frequency
sound waves too high for human hearing-to separate and disperse the platelets.
It's a technology Grewell knows a lot about: he worked for 10 years in research
and development for the Branson Ultrasonics Corp. of Danbury, Conn.,
and used ultrasonics to freeze strawberries, process rice and handle many other
According to Grewell, the potential applications for
plastics created with crop proteins include disposable wraps for hay bales,
pots for plants and packaging for the food industry.
For additional information, contact David
Grewell at (515) 294-2036 or firstname.lastname@example.org.
Iowa State's website is located at www.iastate.edu.