SOCORRO, N.M. – The U.S. Department of Energy recently announced $25 million in funding for 10 research projects in their Basic Energy Sciences (BES) program to build the scientific foundations for polymer upcycling that reuses discarded plastics to make valuable products and to reduce plastics waste.

NMT chemical engineering faculty member Dr. Sanchari Chowdhury along with co-investigators Dr. Youngmin Lee and Dr. John McCoy won a grant for their project, “Development of Recyclable Thermosets for Additive Manufacturing.” The NMT team will receive approximately $800,000 for three years and the grant will support three graduate students.

“My co-investigators, Drs. Youngmin Lee and John McCoy, and I are very excited about this award,” Dr. Chowdhury (pictured at right) said. “This is a true collaborative project and I believe the credit of this award goes to the strong collaborative efforts between me and my co-investigators.  We made a strong team with complementary expertise.”

“Polymer upcycling holds the promise of boosting reuse of plastic waste and lowering the energy costs and impacts of plastic production,” said Dr. Steve Binkley, Acting Director of DOE’s Office of Science. “This research will provide insights into chemical and materials phenomena that will be critical to accelerating developments in this emerging area.”

Large amounts of new polymers are produced globally each year – over 380 million metric tons – accounting for about 6% of the consumption of fossil feedstocks. Less than 15% of discarded waste is recycled with the remainder deposited into landfills, dispersed into the environment, or incinerated, representing the loss of starting material that could be used for more energy-efficient processes and contributing to a global waste contamination problem, including harm to the world’s oceans and marine wildlife. The research projects being funded by DOE this year range from single Principal Investigator (PI) to multi-PI, multi-institution efforts and are led by seven universities and three National Laboratories are chosen to advance the science to enable approaches for chemical upcycling of polymers, targeting energy-efficient reuse of discarded plastics.  Projects were chosen based on peer review under a DOE Funding Opportunity Announcement open to universities, national laboratories, industry, and non-profit research organizations.  The NMT team will study the development of thermosets which can be recycled using broad spectrum light such as sunlight.  Thermosets such as epoxies are an important class of polymers which are extensively used for many applications such as structural materials, protective layers, and adhesives. These thermosetting polymers are known for their stable thermomechanical properties and excellent chemical resistance. 

“When we try to process a polymer, we need to ‘melt’ it,” Chowdhury said. “But epoxies don't melt in the traditional sense. Instead, as their temperature increases, they first become rubbery and then degrade, but do not flow in a manner permitting them to be reprocessed. Epoxies are extremely strong and that makes them good materials for many applications, but at the same time, that characteristic makes them difficult to recycle.”

The NMT team has been tackling this challenge for two years. In the end, they established a new design approach based on a sound understanding of the fundamental science of the materials. Chowdhury said the NMT project has three major aspects: synthesizing thermosetting polymers capable of depolymerization to process and re-process them; developing the recycle process that works instantly, remotely using light, and exclusively at targeted area by the inclusion of photonic nanoparticles; and, finally, tuning the mechanical properties of the polymers suitable for additive manufacturing.

Beyond the printing of upcycled epoxy, The NMT team is exploring applications to self-healing coatings and rejuvenating structural adhesives.

 -- NMT --