Orange Peel Polymer :: ergo Citra-Solv Plastics!
Oranges Are Good For You (And The Earth)
01.20.05 by Dominic Muren
Two of the top stories of the last year have been that world oil production
is peaking, and that climate change is real, and human-caused. And
interestingly, this week, Cornell University researchers announced a new
type of plastic which is a first step toward addressing both problems. Thank
your lucky stars for oranges.
Cornell Scientists announced this week that they had developed a novel
polymer composed of an oily component of orange peels, and carbon dioxide.
Since CO2 is a greenhouse gas currently being held responsible for a large
amount of climate change, sequestering it in non-atmospheric form is a
pressing concern. Hundreds of different ideas, from pumping liquid CO2 to
the bottom of the ocean, to injecting it into abandoned wells have been
proposed, but most are too expensive, or ineffective.
However, if this process could store a viable amount of CO2, the process
could actually be made to make money, since at the end, you would have
saleable plastic. Furthermore, since this plastic requires no petroleum
products (Other than to power the equipment to make it, but this could
utilize a non-petroleum power source), it would ease our need for oil.
This is just the latest and most thorough success in a growing movement to
utilize industrial waste streams as resources. Products like Ultratouch
insulation, which uses offcuts of cotton cloth for fiber, or Smile Plastics
which re-forms reject plastic parts into unique raw plastic sheeting, are
also helping to turn the tide of material use and waste production. Or, on
the pure product end, MIO culture lab converts the waste stream or derelict
manufacturer directly into new products.
So what about your product? Is there some wastestream just waiting for you
to claim it?
Sweet and environmentally beneficial discovery: Plastics made from orange
peel and a greenhouse gas
FOR RELEASE: Jan. 17, 2005
Media contact: David Brand
Professor Geoffrey Coates, left, holds the reactor he used to make a polymer
using a citrus fruit extract and carbon dioxide, as postdoctoral chemistry
associate Scott Allen, center, and chemistry doctoral student Chris Byrne
display other ingredients essential to the novel process. Byrne is holding a
flask of limonene oxide (oxidized orange peel oil), and Allen holds a beaker
containing the polymer they created. Nicola Kountoupes/Cornell University
PhotographyCopyright © Cornell University Click on the image for a
high-resolution version (1800 x 1200 pixels, 1798K)
ITHACA, N.Y. -- A Cornell University research group has made a sweet and
environmentally beneficial discovery -- how to make plastics from citrus
fruits, such as oranges, and carbon dioxide.
In a paper published in a recent issue of the Journal of the American
Chemical Society (Sept. 2004), Geoffrey Coates, a Cornell professor of
chemistry and chemical biology, and his graduate students Chris Byrne and
Scott Allen describe a way to make polymers using limonene oxide and carbon
dioxide, with the help of a novel "helper molecule" -- a catalyst developed
in the researchers' laboratory.
Limonene is a carbon-based compound produced in more than 300 plant species.
In oranges it makes up about 95 percent of the oil in the peel.
In industry, Coates explains, the orange peel oil is extracted for various
uses, such as giving household cleaners their citrus scent. The oil can be
oxidized to create limonene oxide. This is the reactive compound that Coates
and his collaborators used as a building block.
The other building block they used was carbon dioxide (CO2), an atmospheric
gas that has been rising steadily over the past century and a half -- due
largely to the combustion of fossil fuels -- becoming an environmentally
harmful greenhouse gas.
By using their catalyst to combine the limonene oxide and CO2, the Coates
group produced a novel polymer -- called polylimonene carbonate -- that has
many of the characteristics of polystyrene, a petroleum-based plastic
currently used to make many disposable plastic products.
"The polymer is a repeating unit, much like a strand of paper dolls. But
instead of repeating dolls, the components alternate between limonene oxide
and CO2 -- in the polymer," says Coates. Neither limonene oxide nor CO2 form
polymers on their own, but when put together, a promising product is
"Almost every plastic out there, from the polyester in clothing to the
plastics used for food packaging and electronics, goes back to the use of
petroleum as a building block," Coates observes. "If you can get away from
using oil and instead use readily abundant, renewable and cheap resources,
then that's something we need to investigate. What's exciting about this
work is that from completely renewable resources, we were able to make a
plastic with very nice qualities."
The Coates research team is particularly interested in using CO2 as an
alternative building block for polymers. Instead of being pumped into the
atmosphere as a waste product, CO2 could be isolated for use in producing
plastics, such as polylimonene carbonate.
The Coates laboratory comprises 18 chemists, about half of them striving to
make recyclable and biodegradable materials out of cheap, readily available
and environmentally friendly building blocks. "Today we use things once and
throw them away because plastics are cheap and abundant. It won't be like
that in the future," says Coates. "At some point we will look back and say,
'Wow, remember when we would take plastic containers and just throw them
The research was supported by the Packard Foundation fellowship program, the
National Science Foundation, the Cornell Center for Materials Research and
the Cornell University Center for Biotechnology.
Reported and written by graduate student Sarah Davidson, a science writer
intern with Cornell News Service.
Related World Wide Web sites: The following sites provide additional
information on this news release. Some might not be part of the Cornell
University community, and Cornell has no control over their content or
The Coates Research Group:
Geoffrey W. Coates obtained a B.A. degree in chemistry from Wabash College
in 1989 and a Ph.D. in organic chemistry from Stanford University in 1994.
His thesis work, under the direction of Robert M. Waymouth, investigated the
stereoselectivity of metallocene-based Ziegler-Natta catalysts. Following
his doctoral studies, he was an NSF Postdoctoral Fellow with Robert H.
Grubbs at the California Institute of Technology.
During the summer of 1997 he joined the faculty of Cornell University as an
Assistant Professor of Chemistry. He was promoted to Associate Professor in
2001 and Professor in 2002. He is an Alfred P. Sloan Research Fellow, and
has received awards from the NSF (CAREER), MIT Technology Review Magazine
(TR 100 Award), Research Corporation (Innovation Award), Arnold and Mabel
Beckman Foundation (Young Investigator Award), David and Lucile Packard
Foundation (Fellowship in Science and Engineering), ACS (A. C. Cope Scholar,
A. K. Doolittle, and Akron Section Awards), and Dreyfus Foundation (Camille
and Henry Dreyfus New Faculty and Camille Dreyfus Teacher-Scholar Awards).
His main research interests are the design, synthesis, characterization, and
applications of polymers, with an emphasis on catalytic transformations and
the control of stereochemistry.
Mailing Address (Correspondence)
Geoffrey W. Coates
Department of Chemistry and Chemical Biology
Ithaca, NY 14853-1301
Shipping Address (UPS, Express mail)
Geoffrey W. Coates
G-75 Chemistry Research Building
Ithaca, NY 14853-1301
607-255-5447 FAX 607-255-4137
(Note: Postdoc applications sent by email will NOT be accepted)
Coates Group Phone Numbers