Supramolecular Polymer Nanoparticles for Polymer Toughening

Abstract Nanoparticle toughening of polymers has long been constrained by the inherent trade-off between strength and toughness. Here, we report a supramolecular polymer nanoparticle toughening strategy based on an H2G2-type monomer (H2G2-1). During epoxy curing, H2G2-1 undergoes in situ self-assembly into supramolecular polymer nanoparticles (H2G2-NPs), which serve dual roles: acting as physical cross-linking points for reinforcement, while their reversible host–guest interactions function as sacrificial bonds that dissociate under stress to dissipate energy. This strategy ensures uniform nanoparticle dispersion and excellent interfacial compatibility. Compared to neat epoxy, the H2G2-NPs-toughened epoxy exhibits a 92.6% increase in elongation at break, a 66.0% increase in tensile strength, and a 233% increase in toughness, achieving synergistic strengthening and toughening. This work provides a new strategy to make high-performance toughened polymers.