Polymer Science and Engineering’s Thomas Russell Contributes to Landmark Study on Compostable Plastic

Image courtesy DelRe et al., 10.1038/s41586-021-03408-3
Decomposition of plastic over six days (Image courtesy DelRe et al., 10.1038/s41586-021-03408-3)

What to do with plastic? Despite decades of attempts at effective recycling programs, over 90% of the plastic we use ends up in the landfill or as litter. While biodegradable plastic has made headway, it can contaminate otherwise recyclable plastics, takes months to break down with specialized industrial infrastructure, and decomposes into tiny microplastics, which have themselves become a worldwide health concern.

Now however, a team of researchers, led by Ting Xu at UC Berkeley, a Ph.D. graduate of UMass polymer science and engineering, and which includes UMass Amherst’s Thomas P. Russell, Silvio O. Conte Distinguished Professor in Polymer Science and Engineering, has discovered a way to engineer plastics that can completely biodegrade into organic materials right in your own compost bin.

The research, recently published in “Nature,” details the team’s efforts to “nanoconfine” enzymes into plastics. Because enzymes are nature’s way of breaking down just about everything, the team engineered a way to incorporate two different commercial enzymes, Burkholderia cepacian lipase (BC-lipase) and proteinase K, into the two predominant types of biodegradable plastics that we have today, polylactic acid (PLA), a vegetable- based plastic material blended with cornstarch, and polycaprolactone (PCL), a biodegradable polyester.

What resulted was a durable plastic that nonetheless broke down completely in a matter of weeks given nothing more than water and the standard kind of compost many of us have in our backyards. This new approach is also cost-effective and would add only a few cents to the production cost of making a kilogram of new plastic resin.

“This new research is a major step toward overcoming the plastics waste problem and realizing a sustainable world,” says Russell, and the team’s research could soon find its way into our daily lives. A patent has been filed, a startup company created, and further research into composting additional types of plastic is in the planning.