3D Printing of Mechanically Robust Elastomers: Molecular Design and Fabrication with Urea-Containing Photocurable Monomers.

The mechanical properties of UV-cured elastomers for digital light processing (DLP) 3D printing are essential for their practical applications. However, it remains challenging for printed elastomers to achieve both a high mechanical strength and excellent ductility. In this work, a series of novel photocurable monomers containing urea groups were synthesized via a simple one-step method and then used to fabricate mechanically robust elastomers through DLP 3D printing. The UV-cured elastomer systems showed high photopolymerization activity, which was compatible with the DLP 3D printing process. The as-prepared elastomers exhibited a high elongation at break (326%) while maintaining a high mechanical strength (20.7 MPa). The robust mechanical performances are attributed to the presence of urea groups in the molecular structure of photocurable monomers, which could act as physical cross-linking points to effectively dissipate the mechanical energy. In addition, the honeycomblike elastomers printed by DLP printing demonstrated excellent energy absorption capacity and could support a heavy weight (480 times their own weight) without any collapse. This study provides a simple and effective strategy for preparing mechanically robust elastomers for DLP-3D printing.