Research and development with a new generation of plastics made from soybean protein may some day amount to more than just a hill of beans. The United Soybean Board, a consortium of soybean growers and agribusiness, is working with a number of universities to develop the uses of soybean protein as polymer components, which can replace petrochemicals, be cost competitive, and environmentally more friendly.
``We are taking a whole different view of the project than others have,'' said Walter Rupprecht, a former senior scientist for Dow Chemical Co., who is now commercialization manager for plastics for Omnitech Inc., a Midland, Mich., consultancy working with the Soybean Board. ``We are not trying to replace traditional polymers, but to find niches and applications where the use of soy protein makes sense.''
He said researchers are finding early stages of acceptance of soy proteins for polymers, adhesives and other applications.
``For instance, we have had some success with replacement of polyols in urethane foams with soy protein material,'' Rupprecht said. ``We are not trying to replace the whole product, or make a `green' polymer, but just have the soy material be a component.''
Other successes, by research-ers at Michigan State University and Iowa State University, are the development of soy-based blown films for agricultural mulching. The material is similar to polyethylene, and can be made into bags and other products traditionally made of synthetic chemicals.
``We are also working on soy protein end-joint glues, adhesives and coatings, and are looking into use of the soy proteins in extrudable plastic lumber composites,'' Rupprecht said. ``Obviously, the Soybean Board is interested in promoting the use of soybeans, and they are committed to spending about $4 million on this.''
Rupprecht said, however, the soybean researchers are concentrating on practical issues.
``So often with academic projects like this, the claims and goals tend to be very idealistic, and to neglect the practical aspects,'' he said. ``But we are focusing on a different approach; one that takes in the shop floor, and the cost.'' He said so far those cost considerations have shown the soy protein materials to be more expensive, in most cases, than traditional polymers. The researchers are confident they can resolve problems, while maintaining the properties of the soy-based materials and cutting costs, especially in applications like poured foams and some non-food applied films.
``We don't want to build any false expectations, either that this is biodegradable, in the purest sense, or that it can replace traditional resins, but the films do have some attractive anti-static qualities and there is a lot more work to do.''
One job is to convince the industry that the soy-based resins are processable, and that they have qualities competitive with traditional resins, and to convince the consumer that the fact that the resins are ``degradable'' is a benefit.
``We are more comfortable suggesting that the resins are compostable rather than degradable,'' Rupprecht said. ``If you deep-bury something and keep oxygen and water away from it, nothing is degradable, but properly composted, these resins do degrade and leave only natural substance in the environment.''