Building a better plastic from the ground up

Petroleum-based microfibers — polyester and nylon — are washing out of our clothes, flowing right through wastewater treatment plants and on into the Great Lakes. These fibers end up in the bodies of fish, and all the creatures who eat the fish. Plastic micro pellets from face cleansers and lotions share a similar fate.

But it doesn’t have to be that way, says Prof. Marc Hillmyer, director of the Center for Sustainable Polymers at the University of Minnesota, which is supported in-part by Minnesota corn farmers.

Bioplastics made from the plant cellulose in corn and other farm crops could be designed for “programmable degradation.” While in use, these bio polymers would behave like ordinary plastic. Once in the landfill, however, they decompose into environmentally harmless materials — unlike their petroleum based forbears.

Hillmyer’s research focuses on the basic chemistry that would turn cellulose molecules into ‘furfural’ and ‘hydroxymethyl furfural,’ building blocks for polymers that could be used to make an array of products from disposable cutlery, plates and cups; to plastic bags and containers. Even clothing.

“Our research looks at how do you turn (cellulose) into a polymer in efficient ways, and if you can do that, it really raises the value of the molecule you started with,” said Hillmyer.

Thirty-six graduate students take part in the center’s research projects, which have attracted a lot of attention in scientific circles.

“This basic scientific research is a great way to leverage our farmer-funded research dollars,” said Bruce Peterson, a farmer in Northfield, and president of Minnesota Corn Growers Association. “These projects have won grants from the National Science Foundation and other organizations, which makes our contribution go farther.”

The idea of turning biomass into plastic has already experienced commercial success. Everything from plastic forks to pillows to clothing is now manufactured from Polylactic acid (PLA), or, polylactide — a plastic derived from the starch in corn kernels. This new research could turn what is now considered ag waste into a valuable commodity.

Hillmyer believes the Center for Sustainable Polymers is laying the groundwork for the eventual replacement of all fossil-based plastics with renewable sources.