Robust, Recyclable, and Reversibly Adhesive Polysulfide Elastomers via Inverse Vulcanization

Abstract

Inverse vulcanization stands as a transformative strategy for valorizing surplus sulfur into polysulfides; however, inverse vulcanized polysulfides typically necessitate harsh synthetic conditions and suffer from an intrinsic trade-off between mechanical strength and network flexibility, limiting their practical applications. Herein, we report a mild-condition synthetic paradigm for the fabrication of recyclable yet mechanically robust polysulfide elastomers. Specifically, carboxyl-functionalized polysulfide prepolymers were first synthesized through the ternary inverse vulcanization of sulfur, styrene, and thioctic acid, followed by cross-linking with bisphenol A diglycidyl ether to construct tunable network architectures. Systematic modulation of cross-linking density and chain flexibility enabled precise tailoring of thermomechanical properties of the resulting elastomers, achieving a combination of high strength and extensibility. The intrinsic dynamic polysulfide backbone further endows these elastomers with prominent recyclability and healing capabilities. In addition, these elastomers exhibit outstanding adhesive performance, featuring high adhesion strength, reversible bonding on demand, and broad substrate adaptability, making them highly promising candidates for sustainable adhesives.