Superior Impact Resistance in Bionic Nanocellulose Composite Supramolecular Elastomers via Multiple Hydrogen Bonding Interactions

Inspired by biological mechanisms of impact protection, nanocellulose and linear polyurethane molecular chains are simultaneously tailored and expanded using supramolecular chemistry. This approach has led to the development of a novel impact protection strategy that leverages multilevel hydrogen bonding interactions. These abundant interactions effectively hinder the crystallization of polycaprolactone (PCL) chain segments, resulting in uniformly distributed microphase separation. This configuration achieves a significant fracture strength of 47.5 MPa, while maintaining an exceptional elongation at a break of 974.2%. The results demonstrate that supramolecular polyurethane-cellulose nanofiber (SPU-CNF) elastomer significantly reduces impact force and extends the impact buffer time. Crucially, the underlying mechanisms responsible for energy dissipation and impact protection in SPU-CNF are elucidated. To validate these properties, impact protection tests at varying impact rates are conducted, underscoring the potential applications of the proposed SPU-CNF in impact-resistant materials.