(248b) Processable Multiple Network Composite Design Using Insights from Sequential Ipns

‘Double network’ 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.