Generalization of the sacrificial bond principle for gel and elastomer toughening

Although conventional polymer gels are known as mechanically weak materials, their fracture toughness can be effectively improved by introducing weak and brittle bonds into soft and stretchy polymer networks. This toughening method, denoted as the ‘sacrificial bond principle’, has been recently proposed. In this focus review, I describe some extremely tough gels prepared using this principle, e.g., double- or multiple-network gels with high...