Functional Monomer‐Enabled Hierarchical Hydrogen‐Bonding Structure for Impact‐Resistant, Self‐Healing and 3D Printing

Abstract

Developing impact‐resistant materials that simultaneously integrate self‐healing capability and printability remains challenging due to the trade‐offs among energy dissipation, chain mobility, and processability. Herein, we propose a synergistic strategy of combining hierarchical hydrogen bonding with low‐viscosity monomer polymerization to construct a photocurable polyurethane–urea elastomer (APU–HEA) for digital light processing (DLP) 3D printing. By introducing 2‐hydroxyethyl acrylate (HEA), the system achieves reduced viscosity (about 2.8 Pa·s), enhanced chain mobility, and the formation of dynamic hydrogen‐bonding networks. The resulting material exhibits high elongation (2730 ± 52%) and toughness (263 ± 3.1 MJ m −3 ), along with efficient self‐healing (∼91.1 ± 1.2% recovery at 100°C). It also demonstrates excellent printability, enabling fabrication of complex structures with feature sizes below 100 µm. Benefiting from dynamic bond dissociation and reconstruction, the material shows improved intrinsic impact resistance with an energy dissipation ratio of 25%. Furthermore, integrating a lattice architecture yields a material–structure synergistic system, which significantly enhances energy absorption (from 58.0 ± 5.3% to 82.1 ± 9.3%) and reduces peak impact force (from 58.5 ± 6.3 N to 5.8 ± 0.7 N) in helmet protection. This work provides a versatile strategy for designing advanced impact‐resistant polymer systems.