Cooper Tire & Rubber Co. and its consortium partners, including Clemson University, Cornell University, PanAridus and the Agricultural Research Service of the U.S. Department of Agriculture (USDA-ARS), have announced the completion of a five-year, $6.9 million Biomass Research and Development Initiative (BRDI) grant, “Securing the Future of Natural Rubber—an American Tire and Bioenergy Platform from Guayule.” A report on the grant was recently presented at the public-private sector consortium’s wrap-up meeting held at the Cooper Tire & Vehicle Test Center near San Antonio.

Cooper Tire & Rubber Co., working as the lead entity in the consortium, announced at the meeting that its scientists produced several sets of concept passenger car tires in which all the natural and synthetic rubber is replaced by guayule natural rubber. Guayule, a shrub grown primarily in the southwestern United States, contains rubber that can be processed for use in tires. The grant team studied the feasibility of using guayule in tires versus Hevea natural rubber, which is used by the industry today and is sourced primarily from Southeast Asia.

The 100-percent guayule-based concept tires underwent extensive evaluation by Cooper’s technical team, including rigorous wheel and road tests, and were found to have overall performance at least equal to tires made with Hevea and synthetic rubber. The company says the tires performed significantly better in rolling resistance, wet handling and wet braking than their conventional counterparts. Following the meeting, consortium members participated in a ride and drive on the 100-percent guayule concept tires at the Cooper facility.

“Cooper built more than 450 tires, replacing various tire components made with Hevea and synthetic rubber with those made with guayule and testing each for overall performance. With knowledge gathered from these builds, we created the industry’s first all-guayule concept tires and with them conducted rigorous lab and road tests that provide verifiable performance results,” said Chuck Yurkovich, Cooper’s senior vice president of Global Research & Development. “Based on our findings, Cooper could use guayule rubber in tire production tomorrow if enough material was available to meet our production needs at a competitive price. To make this happen, the combined effort of government, agriculture and industry is needed to grow the plants and create large-scale manufacturing operations to produce the rubber for use in the tire industry.”

Consortium member Clemson University reported the completion of a Life Cycle Analysis (LCA) to quantify the environmental impact of producing tires from guayule including materials, energy and emissions from raw material procurement to end of life. In addition, USDA-ARS, which earlier in the BRDI grant cycle completed the most extensive irrigation study of guayule ever conducted, reported the completion of a web-based tool for farmers to access an irrigation model online. The model will allow those growing the guayule plant to utilize research data to manage irrigation water usage for maximizing yields while controlling costs.

ARS also reported on its work under the grant to sequence the guayule genome. This effort was geared to position the crop to benefit from modern genomics tools developed by the Cornell University consortium partners.

Other significant accomplishments over the five-year grant cycle included:

* PanAridus, the project’s raw material supplier, achieved success in manufacturing rubber using improved strains of guayule, producing rubber in quantities never before achieved for use in modern tires. Cooper and PanAridus also improved the rubber extraction process from guayule plants.

* USDA-ARS pioneered direct seeding methods and agronomics.

* Cooper, PanAridus and USDA-ARS worked closely to identify key variables impacting rubber quality. Controlling these factors during the rubber manufacturing process resulted in compounds with properties that are similar to Hevea natural rubber.

* USDA-ARS completed an irrigation study of guayule that compared surface irrigation and subsurface drip irrigation to determine the most effective method to drive higher rubber yield per acre. The study found that drip irrigation provided an enormous benefit over other irrigation techniques and led to improved yields.

“The results of this grant have been groundbreaking,” added Yurkovich. “Never before has it been proven that guayule is a viable source of domestically produced natural rubber for the tire industry. However, through the combined effort of industry, government and academia, the BRDI team has unequivocally demonstrated just that.”