Synthesis of Polydicyclopentadiene Thermosets with High Stretchability and Self-healing Properties via Ring-opening Metathesis Polymerization

Abstract

Thermosetting polymers exhibit outstanding mechanical properties, thermal stability, and chemical resistance due to their permanently cross-linked network structures. However, the irreversible nature of covalent cross-linking renders these materials non-reprocessable and non-recyclable, posing significant environmental challenges. Although healable polymers based on dynamic covalent bonds and supramolecular interactions have emerged as promising alternatives, a broadly applicable strategy utilizing metal-ligand coordination in thermoset systems remains underexplored. In this work, we present a robust and healable thermoset system fabricated via ring-opening metathesis polymerization (ROMP) of commercially available chelating norbornene comonomers. Cross-linking is accomplished through O-donor coordination to Lewis acidic metal centers, yielding polydicyclopentadiene (PDCPD)-based networks that demonstrate high mechanical strength (up to 60.8 MPa) and effective self-healing performance. This methodology offers a simple and scalable approach to developing high-performance, sustainable thermosetting materials.