College of Engineering News • Iowa State University

Cochran biobased paving research team receives national honor

Eric Cochran
Mary Jane Skogen Hagenson and Randy L. Hagenson Professor Eric Cochran

Department of Chemical and Biological Engineering (CBE) Mary Jane Skogen Hagenson and Randy L. Hagenson Professor Eric Cochran is part of a team that has been honored by the American Chemical Society (ACS) at its Spring Meeting.

Cochran, along with Gerald and Audrey Olson Professor R. Christopher Williams of the Department of Civil, Construction and Environmental Engineering, with their industrial partner Donald Sjogren of Seneca Petroleum Company, have received the 2021 Cooperative Research Award in Polymer Science & Engineering. It  honors their research efforts into biobased thermoplastic polymers for paving processes. They were officially recognized at the organization’s mid-April meeting and also provided a lecture on their research, titled “Putting soy-based thermoplastics to work in the construction industry.”

Cochran and R. Christopher Williams of the Dept. of Civil, Construction and Enviromental Engineering
Cochran (right) is pictured with research partner R. Christopher Williams of the Department of Civil, Construction and Environmental Engineering at Iowa State’s BioCentury Research Farm. A specially-built processing facility there has been the development center of the paving research.

After nine years of development, the ISU research team is about to launch a commercial process for a high-oleic soy oil polymer that can replace petroleum-based polymers in asphalt paving. The bio-based binding agent is an economical, efficient and sustainable alternative to highly volatile and expensive chemicals currently used in asphalt pavers with the potential to open a new, large market for soybean growers.

The high oleic soybean oil polymer, known as poly(acrylated epoxidized high oleic soybean oil), or PAEHOSO, is a rubbery polymer that provides crack and rut resistance in pavements formulated with high recycled content and other low cost asphalt sources. PAEHOSO can be produced in soy-based rejuvenating oils that further aid in the rehabilitation of recycled pavements.

The polymer/oil cement, known as “BioMAG,” is manufactured at nearly 100% atom efficiency without the need for organic solvent or polymer finishing steps. To date, 50 tons of BioMAG have been produced by the research group and used in demonstration paving projects in several states throughout the U.S. The first full-scale commercial batch is planned for production this spring.

Donald Sjogren of Senece Petroleum Company
Donald Sjogren of Seneca Petroleum Company is the team’s industrial partner and will share in the American Chemical Society honors.

As an additional benefit from these processes, a substance known as poly(acrylated glycerol), PAG, can be manufactured from crude glycerol as a water soluble adhesive that displaces polymeric diphenylmethane diisocyanate, a chemical substance, in wood composite materials. The team has shown that PAG adhesives can be spray-applied in the same equipment currently used throughout the industry to yield formaldehyde-free fiberboards with reduced PMDI content.

Collaboration continues to scale PAG manufacturing to the multi-ton level to enable full production runs at commercial mills in 2021. About 400 million tons of asphalt are applied each year in the U.S., so the market potential for the newly created soy polymer is significant.

In November 2019, the research team held a well-attended demonstration of their paving material at Iowa State’s BioCentury Research Farm to demonstrate its elasticity and ease of handling.

“It’s been tested by transportation departments in 30 states with more than four million truck loadings, and we’re confident it’s high quality. Along with that, this technology could reduce paving costs by 25%. That’s a very conservative estimate,” said Williams.

Paving demonstration at BioCentury Research Farm
A demonstration of the paving material at Iowa State’s BioCentury Research Farm.

“BioMAG has proven itself in the field over and over as a contractor-friendly means to sustainable heavily trafficked pavements with high recycled content,” Cochran said. He reported demonstrations have already been conducted in Opelika, Ala., Janesville, Wis., St. Joseph, MO, Brainerd, Minn., Indianapolis, Ind., Chicago, Ill, Shutesbury, Mass., and Grimes, Iowa. Additional demonstrations are planned in Alabama, Texas, South Dakota, Nebraska, Indiana and Missouri.

Seneca Petroleum began working with the ISU researchers to develop the paving product. Argo Genesis Chemical LLC, a sister company to Seneca, was significant in helping to build Iowa State’s Bio-Polymer Processing Facility in 2015 at the university’s BioCentury Research Farm and turned it over to ISU to ramp up biopolymer production. Significant investments from the Iowa Soybean Association and the United Soybean Board were leveraged to $13 million from private, state and federal funds to scale up the processes and turn the polymers into commercial products.

Parking lot biobased asphalt paving test
Many tests of the biobased paving process have been carried out in locations around the nation.

Cochran says asphalt paving is only the first use of the polymer; the research team is looking at other applications like preservation treatments for pavements and shingles, compostable impact modifiers, coatings, and adhesives.

The ACS Cooperative Research Award in Polymer Science & Engineering was established in 1992 and is presented annually.