Rational Design of a High‐Strength Tough Hydrogel from Fundamental Principles. Issue 12 (13th May 2021)

• Record Type: Journal Article
• Authors: Chen, Genxin; Zhang, Qiong; Ma, Liya; Zhao, Yang; Ran, Jiabing
• Is Part Of: Macromolecular chemistry and physics. Volume 222:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-13
• Subjects: fundamental principles -- high strength -- hydrogels -- tough materials; Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.202100064
• Languages: English
• ISSNs: 1022-1352

Abstract

Abstract: Currently, polymer‐based hydrogels have found applications in many fields but are faced with a challenge how to reach an optimum trade‐off between strength and toughness. In this regard, two prototypes (i.e., poly(AAm‐ co ‐AA)/CS‐Fe 3+ and poly(AAm‐ co ‐AA)/PVA‐Fe 3+ double‐network (DN) hydrogels), following the fundamental principles, are developed for the first time through constructing covalent/ionic dual cross‐links in the first networks while inducing polymer entanglement/crystallite‐based hidden chains in the second networks. Through systematic investigation of their comprehensive mechanical properties, the rationality of the proof‐of‐concept strategy is verified but some modifications are needed for further improvement. In summary, the synergy of DN structure and integrated irreversible/reversible dual cross‐links in a sacrificing network can formulate an effective energy‐dissipation system for high toughness, high toughness/strain recoverability, and high antifatigue capability. High‐functionality cross‐links based on polymer crystallites in the second network enhance the strength and elasticity of the as‐prepared hydrogels but destroy the flexibility and softness of the matrix phase, therefore sacrificing their stretchability. For optimal hydrogel design, introducing high‐functionality cross‐links in the matrix network while maintaining its flexibility or constructing hidden chains in the sacrificing network may be an ideal strategy to solve the afore‐mentioned problem. Abstract : A novel double‐network hydrogel, following fundamental principles of constructing covalent/ionic dual cross‐links in the first network while constructing hidden chains of polymer crystallites in the second network, is synthesized and characterized. This structural design endows the hydrogel with high strength, high toughness, high toughness/shape recovery capability, and antifatigue capability but sacrifices its stretchability.