Robust, tough, ultra-low-creep and reprocessable rubber enabled by weak supramolecular-interaction-dominated yet strong covalent-bond-assisted reverse design paradigm

Abstract

Covalent adaptive networks (CANs) are the dominant design paradigm of reprocessable rubbers, but permanently face a persistent trade-off between strength and extensibility even if they incorporate sacrificial bonds or filler strategies. To date, integrating excellent strength, high extensibility, stability and reprocessability in one rubber remains a significant challenge. Herein, we propose a simple and efficient strategy to construct a reversible hybrid crosslinked network in epoxidized natural rubber (HC-ENR), namely using weak supramolecular interactions as the dominant network, while also using robust dynamic covalent bonds as an assistant, utilizing the former to construct a dense crosslinked network capable of dynamic dissociation, reconstruction, and a sacrificial bonds effect, while the latter possesses bridging macromolecules and a dynamic exchange reaction feature, eventually endowing HC-ENR with a high strength of 18.2 MPa, a prominent extensibility of 927%, an ultra-low creep of only 0.00024% min⁻¹, and high-retention mechanical properties even after multiple reprocessing cycles. Overall, this work develops an efficient design approach for high-performance reprocessable rubbers, offering positive implications for the sustainable development of the rubber industry.