Repairing polyolefins during mechanical recycling
Radical trap chemistry that restores molecular weight of polyethylene and polypropylene during mechanical recycling, enabling closed-loop polyolefin reuse with properties comparable to virgin materials.
Overview
This solution addresses a critical limitation in polyolefin recycling: chain scission during mechanical processing reduces molecular weight and degrades material properties. By introducing polymerizable radical traps into the recycling stream, the technology reacts with radicals generated during chain scission and couples oligomer fragments end-to-end, restoring high molecular weight polyolefins with properties similar to virgin materials.
The approach is designed to integrate directly into existing mechanical recycling workflows, offering a practical pathway to higher-quality recycled polyolefins without requiring chemical solvents or entirely new processing infrastructure.
Technical specifications
- Radical trap additives designed to capture radicals generated during mechanical chain scission of polyethylene and polypropylene
- Polymerizable trap functionality that enables end-to-end coupling of oligomer fragments to rebuild high molecular weight polymer chains
- Controlled radical chemistry expertise applied to both small molecules and polymers for selective addition and coupling reactions
- Validated coupling strategy that converts chain-end functionalized oligomers back to high molecular weight polyolefins
- Compatibility with polyethylene and polypropylene, the two highest-volume commodity plastics
Technology readiness level
The chemistry has been demonstrated in laboratory-scale experiments: both polyethylene and polypropylene have been converted to chain-end functionalized oligomers during mechanical processing, and these oligomers have been coupled back to high molecular weight polyolefins exhibiting properties comparable to virgin materials. Future work will optimize reaction conditions to operate within real-world mechanical recycling processes and integrate the polymerization step directly into the recycling workflow.
About Colorado State University
Colorado State University is a comprehensive public land‑grant research university with an applied, partnership‑driven culture. Multiple research campuses—including the Fort Collins main campus, a public‑facing Denver site, and a foothills research complex with shared core facilities and pilot‑scale testbeds—enable companies to co‑locate, access instrumentation, and run validation studies. A statewide Extension network and proximity to the Front Range innovation corridor provide streamlined engagement with regional and national industry, while an integrated veterinary teaching hospital supports translational studies. Research is supported by competitive federal funding from agencies such as NSF, NIH, USDA, DOE, and DoD. A dedicated technology transfer office streamlines IP, contracting, and startup formation, with incubator and collaboration space for industry partners.
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