Megan Robertson

Catalyst for Discovery Grant, Univ. of Houston

Megan Robertson, professor in the Cullen College of Engineering, has assembled a team of researchers from across the University of Houston to tackle the global issue of plastic waste by revolutionizing polyolefin recycling.

Working with fellow researchers Maurice Brookhart, Brad Carrow, Olafs Daugulis, Alamgir Karim and Ramanan Krishnamoorti, along with numerous graduate and undergraduate students and postdoctoral fellows, the team is leveraging The Welch Foundation’s $4 million, four-year Catalyst for Discovery Program grant to tackle the challenge of mitigating plastic waste through developing new recycling processes.

Polyolefins, which include polyethylene and polypropylene, represent about 60 percent of global plastics production, but are recycled in low quantities. The team seeks to create new chemical paradigms to improve their recycling and reuse through three approaches: compatibilization, upcycling, and degradability.

“Our team at UH is uniquely situated to address this challenge,” Dr. Robertson said, “due to our deep expertise in catalysts used in olefin polymerization, allowing us to design new polymers with unique functionalities. This, combined with our strengths in polyolefin circularity and polyolefin physical properties, will enable us to develop new routes for reuse and recycling of the materials. Additionally, we will work closely with the newly formed University of Houston Energy Transition Institute and leverage our strong connections with Houston’s plastic waste ecosystem including the petrochemical industry, recyclers, nonprofit organizations and government entities.”

The first goal is to enable recycling without extensive pre-sorting of plastics by molecular composition. The team has identified polymer molecules that can act as stabilizing agents, allowing various types of plastic to be recycled together. The next step is to explore how to match these molecules to various waste streams, reducing cost and streamlining the process.

In upcycling, the team is working to convert single-use plastic waste into long-lasting, value-added products. Such an approach would have dual benefits – keeping plastic out of landfills longer while minimizing the need to make new plastic. The team’s goal is to convert polyolefin waste into thermosets such as polyurethanes used in insulation foams, coatings, furniture, and infrastructure materials.

The third focus is chemical recycling that breaks the plastic waste down into monomers, which can then be used to make polymers again, creating a circular process. However, because polyolefins are very stable – a benefit in many applications – they are energy intensive to break down chemically. The team hopes to create degradable polyolefins that retain their original qualities and functionality but can be chemically recycled multiple times, efficiently and with less energy.

“The Welch Catalyst grant is an amazing resource for our team,” Dr. Robertson said. “Polymers are important to society and improve our quality of life, such as in food preservation and transportation, access to clean water, and new energy technologies. These benefits currently come at a cost, however, through the negative impacts of plastic waste. This project will allow us to play to our strengths and work within a larger team to tackle the challenges of plastic waste and devise new solutions that allow our society to continue to benefit from the use of polymers while mitigating their environmental footprint.”