College of Liberal Arts and Sciences at Iowa State University

Research switch

Chemistry's Richard Larock has made a name for himself in a specific form of chemistry. Now he's heading in a new direction.
"This isn't what I've been doing with my entire career, but we're sure having fun with it now," Richard Larock says. "I would say that at least 95 percent of my research at Iowa State has actually been in other areas."

Larock's major research interest over the nearly 30 years he has been on campus has been in the development of new synthetic organic chemistry methods utilizing palladium as a catalyst to prepare a wide variety of organic compounds, particularly those possessing unusual structures or interesting biological activity. This chemistry has wide utility in the agricultural, chemical and pharmaceutical industries.

"Our methodology is presently being used by three of the largest pharmaceutical companies in the world to prepare indoles useful as migraine headache drugs," said Larock, University Professor of chemistry.

Larock has written four books on organometallic chemistry and organic synthesis, including Comprehensive Organic Transformations, a 2,600-page book and classic reference work in organic synthesis in its second edition.

These days however, Larock's research group has become actively involved in another interesting area. As part of the Center for Crops Utilization Research, Larock, Valerie Sheares, assistant professor of chemistry; and Fengkui Li, a postdoctoral research associate, are developing unique, new plastics based on soybean oil.

"The products we've developed range from very rubbery to good, hard plastics," Larock said.

Larock's interest in the project actually started about six years ago when another postdoctoral fellow, Mark Hanson, discovered that he could make reasonable-looking plastics from soybean oil.

"The program didn't really take off until Dr. Li came along (in 1998)," Larock said. "He has a Ph.D. in polymer chemistry and physics, and he has really made things happen for us on this project. Our goal is to make useful plastic materials. We've already found some interesting thermal and mechanical properties for our plastics."

The researchers have found that the soy plastics have good sound and vibration dampening properties that could allow them to muffle noise and vibrations for a wide variety of appliances and machines.

The materials that Larock's group have developed also exhibit good shape memory properties. Shape memory plastics can be heated, reshaped and cooled to produce new shapes, but when you reheat them they return to their original shape. Plumbers could find this property attractive when connecting two different diameter pipes.

"Most petroleum-based plastics don't do these things," Larock said.

The Iowa Soybean Promotion Board, which has funded Larock’s research for the past five years, recently funded a study to determine the economic feasibility of the soy-based plastics. That market opportunity analysis has identified potential industrial partners and a number of very promising features of this technology.

These include the fact that the materials ranging from tough elastomers to rigid composites can be producted; polymerization is done at relatively low temperatures and pressures; a capital intensive process is not required to produce the materials; and the properties of the plastics can be varied over a wide range.

However, the ready availability of soybean oil and its low cost are probably the most attractive features. Soy oil is 17 cents per pound, while many petroleum-based materials commonly used in plastics are 25 cents a pound and higher. With 60 billion pounds of synthetic plastics produced each year in the U.S. alone, the use of soybean oil in plastics could be a huge economic benefit for soybean farmers.

The ISU Research Foundation has received a patent on the work and the Center for Advanced Technology Development is working closely with the Larock group to try to find an industrial partner to market and produce the various soy plastics including Archer Daniels Midland. Funding has also come from the Iowa Energy Center and the Consortium for Plant Biotechnology Research.

Soybean oil isn't the only oil that Larock and his researchers feel can utilize this process. Reasonable plastics have been produced from corn, fish, tung, peanut, sunflower, walnut and a number of other natural oils.

"This is a very general process," Larock said. "The advantage of soybean oil is that it's the largest commodity oil available and is quite cheap. One of the real attractive features of this project is fact that the starting materials are so readily available and biorenewable and there are many potential uses for the bioplastics. There are lots of very promising directions we can go in."