Unveiling the secrets of plastic biodegradation

According to the United Nations Environmental Program, the equivalent of more than 2,000 garbage trucks full of plastic are dumped into oceans, rivers, and lakes every day.

“The escalating crisis of plastic pollution has shifted the global conversation from how we arrived at this point and more on deciding our future course of action,” said Tolou Shokuhfar, an associate professor in the Richard and Loan Hill Department of Biomedical Engineering. “The potential catastrophic global consequences should the glaciers melt, a situation exacerbated by the relentless dumping of polymers and plastics into the world’s oceans, would not only reshape global geography but also displace millions of people.

Shokuhfar is also the principal investigator for a grant from The Nonwovens Institute, a consortium of international industry, government, and academia professionals to facilitate the development of new fiber-based materials and products. Mechanical and Industrial Engineering UIC Distinguished Professor Alexander Yarin is the co-investigator on the grant.

There has been previous research done to develop biodegradable polymers, however, the applications of these polymers are limited because of physical properties that do not allow them to break down in landfills, soil, or water. In fact, Shokuhfar shared that a recent study found that biodegradable plastic bags could still carry almost five pounds of groceries without breaking even after being in soil or water for years. She added that conventional plastics such as Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), Polyethylene (PE) are derived from petroleum and can take hundreds to thousands of years to degrade. Research shows that biodegradable plastics through new approaches are feasible, but even these newer materials can persist for many years in landfills.

“For example, in measuring the percentage of biodegradation of a new plastic, plastic blend, or polylactic acid (PLA), they take a certain amount of that product that contains that PLA or that specific plastic or polymer to check for biodegradation,” Shokuhfar said. “They take a sample of the soil that contains the microbes, which aid in degradation of the polymers, and they measure it after about one year to reveal how much weight from the plastic has been lost. However, it takes a long time to make those measurements and one year does not provide conclusive information to extrapolate it, it doesn’t give us a conclusive measurement of polymer biodegradation, and the industries don’t know how they can enhance the degradation of their plastic pollution.”

She and Yarin’s research is aiming to create a multi-scale approach to address this crisis. Specifically, she noted that an investigation with these novel approaches can provide a lot of information to industries, especially nonwoven industries, which are a major producer of plastics and polymers.

They are using transmission electron microscopy and spectroscopy to provide real-time measurements of biodegradation.

“We’ll be taking small amounts of plastics, such as modified biodegradable blended PLA, and introduce certain environments including simulated soils and simulated ocean water to measure how much the polymer fibers or nanoplastics are degrading and what the mechanism of the degradation is,” Shokuhfar said.

The ultimate goal of the research is to improve our understanding of biodegradation mechanisms and guide the development of future sustainable plastic materials.

In addition, Shokuhfar and Yarin’s research can impact and inform policymakers, researchers, and environmental agencies on how to address the growing demand for eco-friendly materials and sustainable waste management strategies.

Shokuhfar is working on the experimental side, while Yarin is working on the theoretical aspects of their research in this three-year project.