Room-Temperature Self-Healable Glassy Semicrystalline Polymers via Ionic Aggregations

Semicrystalline polymers constitute the largest fraction of industrial and engineering plastics but are difficult to automatically self-heal in their glassy state due to the frozen molecular chains. Here, we present a room-temperature autonomous self-healable glassy semicrystalline polymer by incorporating ionic aggregations to its amorphous segments, which shows a crystalline melting temperature (Tm) up to 60 °C, Young’s modulus up to 1.7 GPa, and storage modulus up to 0.5 GPa at 25 °C. By using small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), dynamic mechanical analysis (DMA), and broadband dielectric spectroscopy (BDS), we reveal that ionic aggregations exhibit independent phases and relaxation behavior with a low energy barrier. This enables the relaxation and reconfiguration of adjacent amorphous polymer chains on the fractured surface at room temperature. The resulting polymers exhibit instantons self-healing with a recovered tensile strength of 43.5 MPa and 97.5% healing efficiency within 4 h. This work offers a promising strategy to extend the lifespan, increase the sustainability, and decrease the cost of semicrystalline polymers. As a proof of concept, such room-temperature self-healable glassy semicrystalline polymers can be considerably used in 3D printing manufacturing processes, leading to merged interfaces and enhancing the product’s structural integrity.