Dual Recycling of Depolymerization Catalyst and Biodegradable Polyester that Markedly Outperforms Polyolefins.

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Chemically recyclable polymers are gaining attention for sustainability.
• Developing recyclable catalysts and high-performance polymers simultaneously presents a challenge.
• Circular economy principles necessitate efficient polymer and catalyst recovery.

Purpose of the Study:

• To introduce a dual catalyst/polymer recycling system.
• To achieve selective depolymerization of high-performance biodegradable polymers.
• To demonstrate the recovery and reuse of both polymer and catalyst.

Main Methods:

• Utilized recyclable inorganic phosphomolybdic acid as a catalyst.
• Catalyzed selective depolymerization of poly(δ-valerolactone) in bulk phase.
• Investigated mechanical properties and recyclability of the polymer and catalyst.

Main Results:

• Achieved selective depolymerization of poly(δ-valerolactone) at 100°C with quantitative monomer yield.
• The resulting polymer exhibited outstanding mechanical performance (tensile strength ≈66.6 MPa, fracture strain ≈904%, toughness ≈308 MJ m⁻³).
• Recovered monomer was repolymerized to the original polymer, and the catalyst retained activity after repeated use.

Conclusions:

• The developed system enables efficient, low-temperature, and selective depolymerization of high-performance polymers.
• This approach successfully closes the circular loop for both the polymer and the catalyst.
• The recyclable catalyst and polymer system offers a sustainable alternative to conventional materials.