Tailoring Electromechanical Properties of Natural Rubber Vitrimers by Cross-Linkers

The growing demand for smart polymeric transducers such as dielectric elastomer actuators and energy harvesters has urged the use of sustainable recyclable elastomeric materials. Vitrimer chemistry shed light on future reprocessable thermosets elastomers. In this work, epoxidized natural rubber (ENR) vitrimers were prepared using diacid or triacid cross-linkers formed covalently cross-linking networks via thermally triggered reversible β-hydroxy ester bonds. cross-linked ENR elastomers exhibited Arrhenius-type viscoelastic behavior with a complete stress relaxation between 140 160 °C, that is, vitrimer characteristics, which highly dependent temperature. mechanical properties can be tuned by varying molecular structure concentration cross-linkers. Among cross-linkers, Pripol 1017 fatty polyacid (P1017) 3,3′-dithiopropionic acid (DTPA) had similar effects density vitrimers. highest tensile strength 8.70 ± 1.9 15.6 2.6 MPa was obtained at 6 mol % P1017 DTPA, respectively. While diamide-based cross-linker (DME), 8 needed to reach 13.1 2.7 elastomer. three showed increased relative permittivity ε′ = 5∼7 1 kHz while maintaining low losses compared traditional dicumyl peroxide-cured ENR, 3.57 kHz. With optimized acidic concentrations %, DTPA DME improved actuation capabilities lower electrical fields. Utilizing dynamic tune electromechanical reversibly polymer will open new opportunities devices.