Poly(Ionic Liquid) Double‐Network Elastomers with High‐Impact Resistance Enhanced by Cation‐π Interactions

Abstract With the continuous development of impact protection materials, lightweight, high‐impact resistance, flexibility, and controllable toughness are required. Here, tough and impact‐resistant poly(ionic liquid) (PIL)/poly(hydroxyethyl acrylate) (PHEA) double‐network (DN) elastomers are constructed via multiple cross‐linking of polymer networks and cation‐π interactions of PIL chains. Benefiting from the strong noncovalent cohesion achieved by the cation‐π interactions in PIL chains, the prepared PIL DN elastomers exhibit extraordinary compressive strength (95.24 ± 2.49 MPa) and toughness (55.98 ± 0.66 MJ m −3 ) under high‐velocity impact load (5000 s −1 ). The synthesized PIL DN elastomer combines strength and flexibility to protect fragile items from impact. This strategy provides a new research idea in the field of the next generation of safety and protective materials.