Plastics: Enhancing Recycling and Sustainability

09/01/2022
By Edwin L. Aguirre

Two faculty researchers from the Department of Plastics Engineering have won grants for projects that aim to reduce the amount of plastic that ends up in landfills and the environment each year. Prof. Meg Sobkowicz-Kline and Asst. Teaching Prof. Akshay Kokil were awarded funding totaling $1 million by the National Science Foundation (NSF) and the National Institute of Standards and Technology (NIST), respectively. 

Sobkowicz-Kline’s two-year, $500,000 NSF award for her project, entitled “Melt Mastication for Upcycling of Polyolefins,” will help advance the development of a new manufacturing process to ease the recycling of plastic film packaging—the ubiquitous thin, soft, flexible material used in grocery bags, zip-top storage bags and dry-cleaning bags, as well as in wrapping produce, medical products and many consumer products, including paper plates, napkins, bathroom tissue, diapers and more.

Plastics Engineering Prof. Dave Kazmer is a co-principal investigator in the project, along with Profs. E. Bryan Coughlin and Alan Lesser of UMass Amherst.

Kokil’s three-year, $500,000 NIST grant will support his effort to develop the future workforce needed to grow a circular economy for plastics. Rather than the usual practice of plastics being used once and discarded, plastic materials in a circular economy constantly flow around a “closed-loop” system, retaining their value and prolonging their useful life through repeated reuse, repair and recycling. The materials are discarded only as a last resort.

Kokil is among the scientists and engineers from five research institutions across the country that each received $500,000 in funding from NIST under its first Training for Improving Plastics Circularity Grant Program. In addition to UMass Lowell, the other awardees include Arizona State University, Pittsburg State University in Kansas, the University of Missouri-Kansas City and the University of Southern California.

With Growing Demand, a Growing Challenge

In 2019 alone, single-use, flexible plastic films generated $228 billion in sales worldwide, according to Sobkowicz-Kline, and worldwide demand for flexible films is now estimated to be at around 30 million tons per year. However, the current rate of plastics recycling is just 9%, with the rate even lower for flexible films. These factors contribute to the growing problem of environmental pollution on land and in the oceans.

“New concepts are needed to increase the recycling rate and reduce the amount of waste plastic films ending up in landfills, incinerators and the environment,” she says. 

Sobkowicz-Kline says current film materials are not recyclable because they are composed of layers of different plastics, and thus are challenging to collect, separate, clean and reprocess. “While chemical recycling methods are rapidly evolving, these approaches require high energy input, and the materials’ intrinsic value is lost,” she says. 

Sobkowicz-Kline and her research team are studying a new process to produce plastic film that is made of only a single polymer type, but that retains all the properties that make plastic packaging so attractive, including its low cost, light weight, toughness and effective barrier protection against oxygen and moisture to help maintain food quality and flavor. 

“By limiting the film’s construction to just one material, it will be easier to recycle single-use packaging made from it,” she notes.

“New concepts are needed to increase the recycling rate and reduce the amount of waste plastic films ending up in landfills, incinerators and the environment.” -Prof. Meg Sobkowicz-Kline

Sobkowicz-Kline points out that while other concepts have been created for single-material films, their durability and performance fall short of industry requirements. 

“That is why we will apply, for the first time, a combination of new melt processing techniques to form special crystalline structures within the film that will give it enhanced properties,” she explains. “Along with our partners at UMass Amherst, we will carefully study the material and process factors that combine to create these unique structures so that a circular economy can be realized for plastic films.”

She adds, “Our research has the potential to increase the plastics recycling rate, especially for films, while also maintaining the important benefits of flexible plastic packaging, including food safety, convenience and low carbon footprint.” 

Sobkowicz-Kline’s team also includes plastics engineering master’s student Sarah Perry ’23, Ph.D. students Sixtus Nzeh ’25 and Patrick Casey and postdoctoral researcher Allen Chang.

“Plastic waste cannot be avoided, but it can be reprocessed and upcycled into even better products, providing a huge motivation behind this research group, which I am proud to be a part of,” says Perry, who is from Billerica, Massachusetts.

In addition to running tests of materials and writing reports of experimental results, Perry also prepares and analyzes enzymatic degradation experiments of PET, a widely used plastic in water and soda bottles and other applications, to explore new, green recycling methods.

“Aside from gaining hands-on experience in plastics processing, characterization and testing and the use of various software, working with other students and professors toward a common goal is a life skill and privilege that inspires me to tackle any challenge that I face,” she says. 

In summer, Perry did her internship at Raytheon Technologies in Dallas, Texas. “It was an invaluable experience—I learned a lot, met great people there and discovered that materials and process engineering was a good fit for me!”

Nzeh, who is from Owerri, Nigeria, plans to give back to society after he graduates. 

“The education and training I’m receiving at UMass Lowell are top-notch,” he says. “They are equipping me with the right tools needed to solve problems facing our community as a professional process engineer.”

Training a Future Technical Workforce 

The goal of the NIST’s new program is to develop novel case-study-based learning modules for students who are interested in helping to solve the growing problem of plastic waste. These modules will focus on major areas in plastics engineering—namely materials, product design, processing, characterization and life cycle analysis.

According to the U.S. Environmental Protection Agency, in 2018, the United States produced around 35.7 million tons of plastic waste. Of that amount, only about 8.7% was recycled, 15.8% was burned to produce energy and 75.6% ended up in landfills.

“Making plastics more sustainable and transitioning them to a functioning circular economy has become all the more important, considering the scope of their use in our modern society,” says Kokil. His project, called Plastics Adaptable for Circular Economy (PACE), aims to create, test and disseminate cross-disciplinary, hands-on modules on plastics sustainability and circularity. 

“These modules, developed by all Plastics Engineering faculty members, will help expand the knowledge base and improve critical thinking skills of the nation’s undergraduate and graduate students,” Kokil says. His goal is to be able to transfer the modules into parallel curricula in the departments of Mechanical Engineering, Chemical Engineering, Chemistry and other related fields. 

“With a technically knowledgeable workforce, people will be empowered to work toward making prudent choices and systemic changes in the plastics industry, such that even in a market-driven condition, this important class of material can become truly sustainable,” Kokil says.

“Making plastics more sustainable and transitioning them to a functioning circular economy has become all the more important, considering the scope of their use in our modern society.” -Asst. Teaching Prof. Akshay Kokil

The PACE project is co-led by Sobkowicz-Kline, Kazmer and Asst. Prof. Davide Masato. Plastics engineering undergraduate students will assist teams of department faculty in the development of the learning modules.

“Evaluation of learning outcomes in the classroom will be performed by Assoc. Prof. Jill Lohmeier of the Center for Program Evaluation at UMass Lowell,” Kokil says. “We are also collaborating with The REMADE Institute near Rochester, New York. They will organize a panel of industry experts who will provide us evaluations and feedback on the modules we have developed.”