Mechanical and Fracture Properties of Dynamically Cross-Linked Polymeric Materials

Recently, tough polymer gels have been developed by introducing dynamics cross-links into polymer networks. Here, I review the molecular origins of mechanical and fracture properties for two types of dynamically cross-linked polymer gels, self-healing gels with reversible cross-links and slide-ring gels cross-linked by ring molecules. Self-healing gels show large mechanical hysteresis and high toughness due to the breaking/healing of reversible bonds. The fracture toughness of slide-ring gels is dominated by the sliding distance of slidable cross-links. Furthermore, I introduce a damageless reinforcement strategy to realize tough and instantly recoverable hydrogels utilizing strain-induced crystallization (SIC).