Toughening hydrogels through force-triggered chemical reactions that lengthen polymer strands.

TitleToughening hydrogels through force-triggered chemical reactions that lengthen polymer strands.
Publication TypeJournal Article
Year of Publication2021
AuthorsZ Wang, X Zheng, T Ouchi, TB Kouznetsova, HK Beech, S Av-Ron, T Matsuda, BH Bowser, S Wang, JA Johnson, JA Kalow, BD Olsen, JP Gong, M Rubinstein, and SL Craig
JournalScience (New York, N.Y.)
Volume374
Start Page193
Issue6564
Pagination193 - 196
Date Published10/2021
Abstract

The utility and lifetime of materials made from polymer networks, including hydrogels, depend on their capacity to stretch and resist tearing. In gels and elastomers, those mechanical properties are often limited by the covalent chemical structure of the polymer strands between cross-links, which is typically fixed during the material synthesis. We report polymer networks in which the constituent strands lengthen through force-coupled reactions that are triggered as the strands reach their nominal breaking point. In comparison with networks made from analogous control strands, reactive strand extensions of up to 40% lead to hydrogels that stretch 40 to 50% further and exhibit tear energies that are twice as large. The enhancements are synergistic with those provided by double-network architectures and complement other existing toughening strategies.

DOI10.1126/science.abg2689
Short TitleScience (New York, N.Y.)