Recycling Commercial Black Polystyrene Plastic to Monomer Using Photothermal Conversion
Princeton Docket # 24-4131
Previous recycling technologies have struggled to effectively process black plastics due to their stability and the presence of additives that complicate sorting and recycling. As a result, the recycling rate for these materials has been nearly zero. To solve this environmental challenge, Princeton University researchers have developed an innovative process that leverages photothermal conversion to depolymerize polystyrene plastics, utilizing the pigment already present in black plastics. This process involves irradiating polystyrene-carbon black composites with white LED light, resulting in the production of styrene monomer which can then be further reprocessed. Importantly, this method demonstrates the recyclability of both the monomer and carbon black, paving the way for a fully circular plastics economy. The technology has shown remarkable efficiency when applied to commercial black polystyrene samples, achieving styrene yields of up to 80% in just 5 minutes without the need for additional additives. Additionally, this method only requires a small percentage of black polystyrene in a waste stream (20 weight%) to enable recycling of the entire mixture. This sustainable approach offers a promising solution to the long-standing problem of black plastic recycling, with the potential to revolutionize the industry by enabling a closed-loop economy for these previously challenging materials.
Applications
• Recycling of black polystyrene • Recycling of mixed polystyrene samples with low percentages of black plastic • Production of styrene monomers
Advantages
• Closed-loop recyclability • Simple, cost-effective and rapid processing • No additives required • High-efficiency recycling (up to 80% yield in 5 minutes with sunlight)
Stage of development
This process has been successfully conducted to create styrene monomers from black polystyrene samples and results have been confirmed experimentally
Publications https://chemrxiv.org/engage/chemrxiv/article-details/669ebafb01103d79c54a530c
https://doi.org/10.1002/anie.202308648
Inventors
Erin E. Stache Ph.D. is an assistant professor of Chemistry at Princeton University where her lab specializes in organic chemistry, photochemistry and inorganic chemistry. She received her Ph.D. from the university of Colorado State University.
Sewon Oh is a 5th year Ph.D. student conducting research in Stache Lab. He received his B.S.in chemistry with a strong interest in polymer science. He currently attends Cornell University.
Hanning Jiang is a 4th year Chemistry Ph.D. student who completed her undergraduate degree at Purdue University. She joined the Stache Lab with aspirations of finding solutions to reduce plastic pollution.
Intellectual Property & Development status
Patent protection is pending.
Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.
Contact
Prabhpreet Gill
Princeton University Office of Technology Licensing • (609)258-3653 • psgill@princeton.edu