June 20, 1996

Contacts:
Jay-lin Jane, Food Science and Human Nutrition, (515) 294-9892
Brian Meyer, Agricultural Information, (515) 294-0706

EDITOR'S NOTE: This release was provided to the Iowa Soybean Promotion Board for its annual Soybean Supplement.

ISU STUDIES SOY-PROTEIN FILMS TO REDUCE PLASTIC POLLUTION

AMES, Iowa -- Soybeans may offer relief to environmental headaches caused by trash bags, crop mulches and other nondegradable plastic-film products, say Iowa State University scientists.

"Polyethylene films are used to make agricultural mulch films, garbage bags, paper coatings, laminating materials and other products," said Jay-lin Jane, a professor of food science and human nutrition.

"Because they don't degrade in the environment, they can cause severe pollution problems," Jane said. "Bags litter beaches and streets. Plastics can harm wildlife, especially aquatic animals. Mulch films can block underground water circulation and hurt soil quality."

Jane and other ISU researchers are working to develop plastic films made with soybean protein that will degrade in the environment. "If we can develop soy-based materials to replace polyethylene films, it would help address pollution problems and open up a new market for soybean products," Jane said.

In the U.S., about 12 billion pounds of polyethylene films are produced annually. Mulch films used to protect crops are used on about 250,000 acres.

With support from the Iowa Soybean Promotion Board, Jane's research has demonstrated that soy-based biodegradable films can be made using blowing extrusion, the same technology used to make polyethylene films.

"Soy-based biodegradable films have some attractive properties as packaging materials, including the ability to block ultraviolet light," she said. "Polyethylene films are transparent to UV light, which can produce chemical reactions or oxidations that deteriorate the quality of the products."

As agricultural mulch films, soy-based plastics may even help improve soil quality. "After they degrade, they may act as a soil conditioner," Jane said. "Preliminary studies show ground soy powder can be utilized by plants, helping them grow."

Research is focused on improving traits of soy-based biodegradable films. To do that, the researchers need to understand more about soy protein's basic properties. With funding from the United Soybean Board, Jane and other ISU scientists plan to establish a database on using soy protein for plastic materials.

"Plastic makers have long-established databases for making polyethylene and other synthetic plastic products. For soy protein, there's a lot of information missing. We hope to fill in some of those gaps," Jane said. "We need to be able to ensure the quality and consistency of soy protein in plastic products."

Besides plastic films, Jane and her co-workers are developing other kinds of soy-based plastics, including those used in extruded-foam products like plates, fast-food "clam shell" containers and construction materials, and in injection-molded products like utensils and golf tees.

Jane, who holds several patents for her work, said interest remains high among companies looking for more environmentally friendly consumer products.

News Releases Agriculture in Action Ag Online Communications Skills Home