This method of precise metathesis polymerization chemically recycles polyethylene by incorporating precisely placed functional groups into the polymer backbone. Plastic waste disposal poses a challenge globally, generating thousands of tons of waste plastics every day. Traditional disposal methods, like landfilling and incineration pose problems, including groundwater and air pollution, as well as harm the health of animals and plants. Existing recycling methods are ineffective for many plastics, especially multi-layer films containing metals. Traditional polyethylene and polypropylene plastics are nearly impossible to degrade, accumulating in landfills and polluting the environment. Many advanced recycling or degradable plastic solutions require specialized processing equipment, limiting adoption and increasing costs.
Researchers at the University of Florida have developed a high-performance method for rendering plastic recyclable by inserting precisely placed in-chain functional groups in the polymer backbone of ultra-high molecular weight polyethylenes. In turn, polyethylene is efficiently broken down and is compatible with standard manufacturing equipment. The functional groups possess strong dipole moments and can induce strong interactions between polymers, thereby yielding strong materials. The process is designed for industrial scalability, using bulk, solvent-free polymerization, supporting a wide range of applications and is adaptable to multiple catalyst systems for cost and efficiency optimization. It positions manufacturers to meet the demand for sustainable materials without sacrificing performance and is a practical and scalable solution for the circular plastics economy.
High-performance, chemically recyclable plastics disassemble polymers at the time of disposal
This technology leverages advanced metathesis polymerization methods to create plastics with in-chain functional group, such as carbonate, urea, thiourea, acid anhydride, and phosphonic acid, precisely positioned within the polymer backbone. The synthesis employs catalysts (molybdenum, niobium, or ruthenium-based) and monomers designed for high-temperature, bulk polymerization. Intensive mixing ensures uniform polymer formation and high molecular weight. At end-of-life, these polymers are chemically disassembled by exposing them to water heated to high-temperatures, breaking them down into reusable building blocks. The process is compatible with various polymerization techniques, including ADMET, ROMP, ring-closure, and olefin exchange, allowing for broad material customization and application flexibility.