Development of Bio-Based Polymers for Use in Asphalt – Phase II

Project Details



17-607, TR-720








Iowa Department of Transportation
Iowa Highway Research Board

Principal Investigator
Chris Williams

Director, AMPP

About the research

The opportunity to produce a high-value material derived from vegetable oils from the Midwest creates a tremendous economic opportunity to replace a dangerous and carcinogenic material in butadiene, which is derived from crude oil petroleum. The majority of butadiene is imported to use for subsequent production of polymers or is contained in polymers imported to the US.

Development of the biopolymer technology for asphalt paving was originally sponsored by the Iowa Highway Research Board (IHRB) under a special funding mechanism for high-risk/high-potential-pay-off research. The biopolymers developed by Iowa State were found to be an excellent alternative to the polymers currently used.

Since the conclusion of the first phase of this study in April 2014, a ton-per-day pilot plant was designed and built at Iowa State University’s BioCentury Research Farm, west of Ames, at a cost of more than $6 million. The pilot plant was installed in late 2015, winterized for the 2015-2016 winter, and reopened in spring 2016.

The research team worked since the completion of the Phase I IHRB project in getting the pilot plant working and calibrated correctly. The Bio-Polymer Processing Facility underwent rigorous troubleshooting and upgrading during 2016 and is now capable of producing biopolymers in sufficient quantities to conduct field demonstration paving projects.

The research now needs to evaluate typical mix designs consisting of both the developed biopolymers derived from vegetable oils and the commercial ones now commonly used and derived from crude petroleum. The biopolymer will be provided at no cost to the research nor to the paving projects.

The research team will initially identify low risk locations, such as low-volume roads and/or shoulders for placement of mixes with the biopolymer-modified asphalt binders to ensure production and placement goes as expected. Once success is demonstrated, higher volume roads will be paved with mixes containing the binder. The researchers propose use of the biopolymers in at least six paving projects.

During the field trial process, the research team will work with the asphalt terminal suppliers in blending the biopolymers to ensure the biopolymer-modified asphalt meets the binder grade requirements. The team will work with the paving contractors for development of the mix designs, which will include laboratory mix performance testing, and coordinate with the contractors on the mix production and placement.

This project will be beneficial in demonstrating that the performance of the biopolymers developed meet expectations and are cost advantaged. The outcome will be the development of a biopolymer that is cost and performance advantaged for use in Iowa roads.

This project will also be beneficial in the development of new materials produced from Iowa feedstock materials (e.g., vegetable oils) and produced in Iowa. This research has the ability to have substantial impact on the Iowa economy through job creation, future tax revenue, and the export of a high value specialty product, which has also shown success in numerous other applications, including adhesives, coatings, and packaging materials.