Sawdust pellets.

MN Impact: University of Minnesota researchers have developed new generations of lignin-based plastics

November 6, 2019

Objective

Research will lead to the development of new and improved forms of renewable, biodegradable plastics (reported as the percent of lignin content used in new product).

Issue

Lignin-based plastics are eco-friendly alternatives to traditional petroleum-based plastics. However, even the best current lignin-based plastics, and especially their mechanical properties, leave much room for improvement.

What has been done

Previous formulations are limited in the amount of lignin that can be incorporated into the final plastic. These materials exhibit significant deterioration in properties with lignin content higher than 35-40 percent.

Simo Sarkanen and his team have developed new generations of lignin-based plastics using processes that can be easily scaled to industrial volumes. For the first time, innovative lignin plastics with very high lignin content exhibit properties comparable or even superior to conventional polystyrene and polyethylene plastics.

Results

The high-lignin-content plastics and polymeric materials show promising tensile strengths (>50 MPa) with formulations using 85-100 percent lignin levels. Not only are these plastics stronger than previous lignin-based plastics, but they add value to the bio-refining and pulp industries that produce lignin as a byproduct and most often burn it for its fuel value.

This technology offers a route to realizing significant commercial value from lignin in the form of a new renewable, biodegradable plastic. It is generally recognized that the profitable conversion of lignocellulosic polysaccharides to liquid fuels and organic chemicals depends on the successful valorization of the lignin in the starting plant materials (including wood).