Engineering\nof β‑Hydroxyl Esters into Elastomer–Nanoparticle\nInterface toward Malleable, Robust, and Reprocessable Vitrimer Composites

Abstract

Rubbers are strategically\nimportant due to their indispensable applications in the daily life\nand high-tech fields. For their real-world applications, the covalent\ncross-linking, reinforcement, and malleability of rubbers are three\nimportant issues because they are closely related to the elasticity,\nmechanical properties, and recycling of the rubber materials. Herein,\nwe demonstrate a simple way to prepare covalently cross-linked yet\nrecyclable and robust elastomeric vitrimer composites by incorporating\nexchangeable β-hydroxyl ester bonds into the elastomer–nanoparticle\ninterface using epoxy group-functionalized silica (Esilica) as both\ncross-linker and reinforcement in carboxyl group-grafted styrene-butadiene\nrubber (CSBR). The Esilica-cross-linked CSBR composites exhibit promising\nmechanical properties due to the covalent linkages in the interface\nand fine silica dispersion in the matrix. In addition, the interface\ncan undergo dynamic reshuffling via transesterification reactions\nto alter network topology at high temperatures, conferring the resulting\ncomposites the ability to be reshaped and recycled.