Hierarchical hard-phase-induced phase-separation toward high-strength, tough, and impact-resistant supramolecular polymers

Abstract

High-performance and self-healing polymeric materials are indispensable for flexible electronics. Advanced polymers are now expected to integrate high strength, large extensibility, excellent toughness, intrinsic self-healing, and recyclability within a single molecular framework. Here, we report a hierarchical hard-phase-induced phase-separation strategy to construct a supramolecular polymer composed of polyimide (PI) and polyurea (PUU), denoted as PIU. The synergistic aggregation of rigid segments drives the formation of hierarchical hard-phases with overlapping size distributions. Their coexistence establishes a continuous load-transfer network that effectively suppresses local stress concentration. Consequently, PIU achieves a tensile strength of 71 MPa, elongation at break of 822%, and toughness of 458 MJ m−3. The dynamic H-bond network endows the material with intrinsic self-healing capabilities. Interfacial interactions enable Carbon Fiber (CF)/PIU composites to achieve superior adhesion and structural integrity. The polymer demonstrates exceptional impact resistance, shielding fragile electronics from drop-weight impacts. These findings demonstrate this strategy offers a scalable design framework for constructing next-generation high-performance materials.