Traditionally, the materials used to form flexible polyurethane foams for industrial applications are derived from petrochemical resources such as glycerin and ethylene oxide.

Many in the auto industry are experimenting with a 5% soy-based polyol.

Five percent is relatively easy, a nice walk-before-you-run application, but there really isn’t a solid business case to do it. We’re talking about only 2% biomaterial for the total foam product. At 40%, which was formulated in our lab by our researchers, we have the ability to make a significant impact on the environment, while reducing our dependency on imported petroleum.

— Dr. Matthew Zaluzec, manager of Ford’s Materials Research & Advanced Engineering Department

Initial projections estimate that using a soy-based foam at high volumes could represent an annual material cost savings of as much as $26 million. As for the potential environmental benefit, according to the National Institute of Standards and Technology, soy polyols have only one-quarter the level of total environmental impact of petroleum-based ingredients.

Ford first showcased its work with soy foams in 2003 on the Model U concept, which featured soy-based seat cushions as well as a soy-based resin composite tailgate. The Model T once contained 60 pounds of soybeans in its paint and molded plastic parts.

Ford has applied for two patents on the soy-based foam, one for high-content soy foam formulations and the other for a novel, low-odor process to synthesize polyols.

For some time, Ford researchers had been hitting a road block with the 40% soy-based foam because of its odd odor, reminiscent of vegetable oil. According to Formulation Chemist Christine Perry, that issue is now resolved thanks to a new synthesis method for soy polyol. The new process utilizes room temperature UV light instead of high heat and catalysts to make the soy polyol.

Using high temperatures for the chemical reaction can cause numerous side products, which produce the rancid odor. It also requires a metal catalyst and more energy. With our breakthrough UV process, we have a simple reaction that is readily controlled by time of exposure, is inexpensive, and reduces the odor.

—Christine Perry

The actual foam is created by combining the 40/60 blend of soy- and petro-based polyol with an isocyanate cross-linking agent and nine other additives in precise combinations. Extensive testing of high and low soy percentages revealed that a 40% to 50% soy substitution produced a product with properties most similar to the 100% petroleum-based polyol foam.

The end product is a soy-based foam that exhibits the desired automotive properties for seating applications such as seat cushions, seat backs, armrests and head restraints. The foam’s chemistry can also be altered as needed depending on factors such as the geometry of a part or required hardness of the foam.

Bayer MaterialScience LLC made significant contributions to the foam’s formulation development, according to Ford.

For the past three years, the project has received funding from the United Soybean Board (USB), a group of farmers/leaders that oversees investments in soy-based technologies. To date, Ford is the only auto manufacturer financially supported by the USB.

Resources:

• “Soybean oil auto applications”; Industrial Biotechnology, Spring 2005

• The Bio-Car Initiative

• Soy vs. Petro Polyols: A Life-Cycle Comparison