Researchers at the University of Minnesota has found a better way to recycle a versatile plastic material, called polyurethanes, that could prevent the material from becoming waste. In the past, a few methods have attempted to recycle polyurethane waste, but these techniques result in a material of lower quality. Now, researchers have found a way to recycle used polyurethanes into equivalent or even higher quality material using an innovative method.
Discovery of the New Process
The researchers ground up polyurethane foam or film and then mixed the particles in a catalyst solution. After drying, the particles were compression molded to form new films. Compression molded films formed good-quality products, but compression molded foam produced cracked and inhomogeneous materials.
The researchers solved this problem by developing a twin-screw extrusion process that improved mixing and air removal in recycled foams, compared to the compression molding approach. Researchers say this new method could be used for continuous recycling of the large amounts of polyurethanes waste currently in landfills and newly produced.
The extrusion process removes air simultaneously as the catalyst enables the polyurethane to flow like a liquid. The reactive process is like those already used in the plastics industry for other purposes meaning the technology could have impact quickly.
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We are quite excited about this new research from the Center for Sustainable Polymers because of the tremendous potential for recycling of polyurethane materials that are typically considered as waste,” said Marc Hillmyer, director of the Center for Sustainable Polymers based at the University of Minnesota and a chemistry professor at the University of Minnesota.
“It also demonstrates how the powerful combination of polymer chemistry and polymer processing can be applied to help solve environmental problems.”
Source: University of Minnesota