âDouble networkâ architectures are used to make hydrogel materials which are incredibly tough despite consisting mostly of water. An important subset of these sequential interpenetrating networks are characterized by a combination of strength and toughness which is attributed to the dissipation of energy by sacrificial breaking of a minority population of load-bearing, highly stretched chains while macroscopic cracks are arrested by the bridging action of a majority population of long chains. These design guidelines have also been extended to non-solvated elastomeric systems. Although the concept has been known in the literature for upwards of 15 years, commercial application is hampered by challenges in processability: the sequential nature of the preparation which is necessary to achieve high degrees of chain stretching makes precision shaping of the material quite challenging. We propose a processable elastomeric composite material platform based on multiple network design guidelines. The material is soft, strain-hardening, tough, transparent, and importantly shows very little hysteresis. The thermoset material starts as a viscous liquid which can be cured in a mold, applied as a coating, or 3D printed. Based on a molecular model of multinetwork elastomers, we explore the potential property space of the composite.
