Understanding how the crystal structure of a new polymer material affects its usefulness as a replacement for a common oil-based plastic was the focus of a research project recently completed by a University of Wisconsin–Madison team.
“We have developed a method using transmission x-ray diffraction experiment and precise data analysis to study the crystalline structure of PET and PEF films,” said Rui Liu, a postdoc in Paul Evans’s lab in the UW Materials Science and Engineering Department who managed the project. Liu is referring to the polymers PET poly(ethylene terpthalate) and PEF poly(ethylene-2,5-furanoate), which are, respectively, a widely used packaging material made from oil and a promising replacement.
This project was funded by the University of Wisconsin Advanced Materials Industrial Consortium (AMIC) as part of the organization’s 2021 seed program for promising industrial-academic collaborations. The work was supported with in-kind contributions from partnering company, Amcor.
The goal was to fill a gap in the understanding of PEF, which is a potential alternative for PET in flexible packaging applications. Liu collaborated with Jesse Feng and Kevin Nelson, engineers from Amcor, a Wisconsin packaging and container manufacturer.
“Currently, Amcor’s primary research efforts emphasize matching the compositions of its packaging products with the global recycling infrastructure. To take advantage of the recyclability of polyesters, understanding the fundamentals of emerging polyesters like PEF will help us better utilize them in a variety of packaging platforms,” said Nelson.
Liu’s team developed a method to study the crystalline structure of oriented PET and PEF thin films to determine the best processing conditions for PEF. It is known that the orientation of molecules within PEF can improve various properties of the material. However, the impact of orientation of its crystal structure on the gas-barrier properties is not well understood. The project successfully developed a method to study the crystallinity and orientation of these polymer films.
“By the end, we were able to determine that the polymer chains in uniaxially stretched PET films are very well oriented and that uniaxially stretched PEF films have a much lower degree of crystallinity,” said Liu. “Biaxially stretched PEF shows a higher degree of crystallinity and a better orientation preference, which can be used to improve the processing conditions for PEF films.”
As leader of the project, Liu refined his skills in proposal writing, budget planning, guiding team members, and writing final reports. He also brought on board Marlee Newman, a graduate student at the UW–Madison, to participate in the development of the experimental methods and the performance of the project.
“Working with industrial collaborators through AMIC is a unique experience in my career and has been extremely valuable to me as an early-career researcher,” said Liu. “The project forced me to think like a principal investigator and gave me a higher level of understanding of research operations.”
“I will be working as an R&D engineer, so being able to design my own experiment for this project will be very helpful for me in my future career,” said Newman.
With this project completed, Amcor plans to continue to pursue related research, including with other researchers at UW–Madison.
Newman has given presentations based on the work at the Facility Days Open House event at the UW–Madison in Fall 2021. Liu reported the outcomes at the AMIC Annual Meeting in April.
AMIC Seed projects are conducted by a single or a small team of UW–Madison graduate students and/or postdocs who are advised by a faculty member. For these young researchers, the goal of the AMIC Seed program is to provide experience working with an industrial partner on a project, from defining the problem and creating a proposal to meeting project milestones, managing a budget, and creating reports.
For participating companies, the AMIC Seed Program provides a rare opportunity to explore scientific questions while building collaborative relationships with promising young scientists and engineers. The proposal ideas originate with AMIC member companies, who submit research topics of interest. These ideas are then developed into proposals by students and postdocs working in collaboration with the companies’ own scientists and engineers.
ABOUT THE UW AMIC
The University of Wisconsin Advanced Materials Industrial Consortium (AMIC) is a group of industrial and academic members created to leverage the broad spectrum of materials science resources and capabilities found in both the university as well as corporate settings throughout the region. AMIC does this by promoting synergies between materials researchers and technologists, facilitating access to personnel and infrastructure, enhancing student experiences with industry for professional development, and facilitating recruitment of a strong and diverse regional network of industry-based materials researchers. The UW AMIC is led by the Wisconsin Materials Research Science and Engineering Center (MRSEC).
Amcor is a major supplier of flexible and rigid packaging used by leading food and consumer products, healthcare and other companies worldwide. Amcor manufactures in over 40 countries and employs approximately 48,000 individuals. Amcor has a strong technical base in polymer chemistry, film extrusion, coating and laminating, printing, and converting. Amcor packaging provides moisture and oxygen barrier that reduces food spoilage, helps keep bacteria at bay and maximizes product freshness. For medical and pharmaceutical applications, Amcor packaging ensures product sterility is not compromised from the point of package filling until it is opened.