Researchers in Iowa State’s departments of chemistry, food science and human nutrition have been playing around with soybean oil, starches and proteins in order to develop improved oil-based products and biodegradable plastics.

Richard Larock and Valerie Sheares, professors of chemistry, have a joint grant from the Iowa Soybean Promotion Board to do soybean research. Their work usually involves taking the fatty-acid chains in soybean oil and either rearranging or breaking the bonds between carbon atoms.

Jay-Lin Jane, a professor in the food science and human nutrition and the agronomy departments, has used starch and protein components of soybeans to produce plastic-like golf tees and spoons. Larock has used his soy-derived varnish to coat Jane’s golf tees, yielding a professional-style product.

But biodegradable tires might prove to be the most useful result of soybean research, Sheares said.

“My favorite future application for this is in tires,” Sheares said. “Rubber tires usually are made of a combination of two things — polybutadiene and polystyrene, which is like Styrofoam. Soybean oil polymers could take the place of the styrene, the synthetic, so they could make tires more biodegradable.”

Larock said soybeans are a cheap, readily available and renewable natural resource. They are sturdy, biodegradable and environmentally friendly. He added that they are more economical than rubber and plastic.

“We take soybean oil — regular soybean oil like you would buy in the grocery store — and we do a kind of catalysis reaction on it that causes it to polymerize. In other words, it goes from a bunch of single soy-bean oil molecules to being a group of soybean oil molecules joined together, and those are polymers, or plastic-like materials,” Sheares said.

She said soybean polymers range in properties, depending on how the reaction is conducted. “We get things that range from oils all the way to waxes, or even solid, plastic-like or rubber-like materials,” she said.

There are two main ways the researchers derive the new materials, Larack said.

One way is to conjugate the soybean oil, which involves using a transition metal as a catalyst, resulting in a better drying oil that is useful for paints, ink and furniture polish, Larock said.

Larock said research indicates the incorporation of conjugated soybean oils in nutrition supplements has the potential to reduce body fat and protect muscle tone.

The other method Larock uses is known as metathesis, which involves chemically rearranging the atoms allowing them to reconnect with other molecules, Larock said, which produces other forms of rubber- and plastic-like materials.

In her research, Sheares uses a third technique, similar to metathesis. She uses heat to induce the oxygen in air to act as the catalyst. This results in a chain reaction which produces new polymers, a process called free-radical polymerization.

“I anticipate free-radical polymerization as being very useful for producing co-polymers, or combinations of different polymers,” Sheares said.