Bulk Energy Dissipation Driven Multiple Hydrogen-Bonded Elastomer Enables High Stretchability, Extreme Softness and Superior Adhesion

The inherent conflict between interfacial toughness and bulk energy dissipation in elastomers poses a challenge for achieving optimal adhesion. Here, this work reports a molecular design strategy for constructing poly(urethane-urea-thioctic acid) (PU-TA) elastomers with superior adhesive properties (adhesion strength of 611 ± 22 kPa and adhesion energy of 2723 ± 82 J m −2 ), high stretchability (8579%), and excellent softness (low Young's modulus of 147 kPa). This is realized via introducing multiple hydrogen bonds (H-bonds) into the PU-TA elastomers: The H-bonds at interfaces establish interfacial linkage, and the bulk H-bonds inhibit the chain segments, resulting in high fracture energy. Furthermore, a correlation analysis demonstrates that bulk energy dissipation dominates role key in regulation of adhesion energy compared with interfacial toughness. This molecular-level strategy provides a new sight into the design of superior adhesives suitable for diverse applications in the field of advanced packaging.