Approximately 450 million tons of plastic are discarded globally, with a mere 9% being recycled every year. Traditional recycling processes degrade the quality of plastics over time, limiting their reuse and value. However, ORNL’s polymer editing technique addresses these challenges by precisely rearranging the molecular building blocks of polymers to create new, high-value macromolecules.
“This isn’t the typical ‘melt and hope for the best’ scenario,” explained Jeffrey Foster, the lead researcher. “Instead of degrading polymers, we’re editing their molecular structure to maintain and enhance their performance.”
The researchers employed advanced metathesis processes, including ring-opening metathesis polymerization and cross metathesis. These processes break and reform double bonds in the carbon chains of polymers, enabling the incorporation of new molecular subunits. The method begins by dissolving waste polymers, such as soft polybutadiene from tires and acrylonitrile butadiene styrene (ABS) used in consumer products, into a solvent and conducting chemical reactions at a low temperature of 40°C.
A ruthenium catalyst drives the reaction, facilitating the formation of durable polymer chains with tailored properties. This precision allows the creation of plastics that are softer, stretchier, or more durable than the original material while conserving nearly all the input material, achieving high atom economy.
ORNL’s method offers multiple advantages over traditional recycling. It consumes less energy, generates fewer emissions, and creates materials with enhanced functionality. Additionally, this technology could expand the range of recyclable polymers, addressing waste streams that were previously deemed unusable.
“This process could make a significant impact by conserving materials and energy that would otherwise end up in landfills,” Foster noted.
The researchers envision scaling the technology to upcycle a broader range of polymers and even create high-performance thermoset materials like epoxy resins and polyurethane. These materials, which are typically difficult to recycle due to their cross-linked molecular structures, could be repurposed for advanced applications.
By leveraging ORNL’s cutting-edge polymer editing, industries can move closer to a circular economy, where plastic waste becomes a resource rather than a liability. With the ability to integrate sustainability and profitability, this innovation offers hope for businesses and the planet.