Nanophase Separation and Interfacial Entanglements Enables Tough Polymer Network†

Abstract

Elastomers and hydrogels are essential components in soft robotics and biomedical devices due to their flexible and swollen polymer network. However, designing soft polymeric materials that reconcile tunable water content and mechanical performance remains a key challenge. Here, we report hybrid polymer networks toughened by nanoscopic arrested phases. As-prepared, dry elastomeric networks demonstrate 4 to 25 folds synergistic enhancement in ductility, while maintaining high moduli and strength. When fully hydrated, the blend gels display tunable swelling ratio (150 -413%), modulus across 2 orders (6.4-200 MPa), high elongation (230 - 410%) and toughness (2.5 -4.4 kJ/m2). Such properties are rarely accessible in conventional gels. Morphological investigation reveals distinct reinforcing nanophases of hydrophobic chains, while viscoelastic measurement shows dense entanglements. This platform bypasses traditional solution-based methods, offering a scalable route to tough, functional hydrogels. Our findings establish a blueprint for soft, multiphase materials for soft actuators or biomedical implants.