Captured carbon dioxide could yield strong, flexible plastics designed for recycling

Scientists at Colorado State University have created a novel method to convert carbon dioxide into recyclable, high-performance plastics that could serve as alternatives to conventional plastics in numerous applications. This breakthrough, detailed in the journal Nature, marks a significant advancement in efforts to reduce plastic waste and promote environmental sustainability through a circular economy model. The study outlines a closed-loop system that transforms inexpensive carbon dioxide into a new class of materials using a chemical reaction involving a compound known as bicycloalkane, initiated by an organic catalyst. The research team, led by University Distinguished Professor Eugene Chen and including postdoctoral researcher Min Zhu as the lead author, has developed a process that enables the formation of durable, customizable synthetic plastics. These materials demonstrate exceptional stability, resisting damage from heat or chemical exposure. They also possess desirable traits such as high mechanical strength and flexibility. Importantly, the fundamental components of these new plastics can be reclaimed through recycling after their intended use. Chen, who holds the John K. Stille Endowed Chair in CSU’s College of Natural Sciences and serves as the Millennial Professor of Polymer Science and Sustainability in the Department of Chemistry, explained that scientists have long sought methods to harness the potential of carbon dioxide for this application. Carbon dioxide is naturally occurring, odorless, non-flammable, abundant, and inexpensive, qualities that make it an attractive candidate for industrial use. However, previous attempts to incorporate it into plastic manufacturing have faced challenges related to maximizing its utility and creating eco-friendly, recyclable polyesters. “Our approach unlocks the potential for carbon dioxide as a renewable and inexpensive resource to produce recyclable polyesters that also exhibit performance advantages and beneficial end-of-life properties,” Chen stated. According to Zhu, the polymers produced through this process can be engineered to match the strength of robust plastics or be softened to resemble rubber, offering versatility in application. The research underscores a broader initiative by Chen focused on sustainability and circular economy principles over several decades. His work aims to minimize waste and pollution by prolonging the lifecycle of materials and designing more environmentally friendly substances. In this particular project, the focus is on repurposing captured carbon dioxide instead of storing it or releasing it into the atmosphere, where it might eventually return to the environment. “We are developing an integrated technology that turns carbon dioxide capture into an intermediate as a building block for the production of sustainable materials of many types and needs,” Chen noted. “We look forward to advancing this further in collaboration with the wider scientific community.” The findings were published in Nature under the title "Alternating CO₂ and bicycloalkane copolymerization to circular polyesters." The publication highlights the potential of this innovation to contribute significantly to global efforts aimed at mitigating climate change and promoting sustainable practices within the plastics industry. Researchers anticipate continued exploration and refinement of this technique, potentially leading to widespread adoption in various sectors requiring durable yet recyclable materials.