Reinforced, Thermal‐Healing and Recyclable Chitosan/Ethylene Propylene Diene Rubber Based on Diels‐Alder Reaction

ABSTRACT Covalent adaptable networks offer a viable approach for producing recyclable rubber materials. Nevertheless, the intricate synthesis process and insufficient mechanical strength limit their commercialization applications. In this study, the reinforced, thermal‐healing, and recyclable chitosan/ethylene propylene diene rubber (CEF‐CS) was synthesized using a solid‐phase blending process via the Diels‐Alder (D‐A) reaction. Furfural modified chitosan (F‐CS) was included as a reinforcing filler and dynamic cross‐linking point into the network formed via the D‐A reaction. The influence of F‐CS content on the mechanical, thermomechanical, and thermal repair characteristics of CEF‐CS composites was examined. The results showed that the CEF‐CS composites exhibited certain mechanical strength and dependable repair capabilities. As the F‐CS content increased, the tensile strength of CEF‐CS composites initially rose and subsequently declined, reaching a peak of 5.1 MPa, which was 5.1 times more than the control without F‐CS. The first healing efficiency of tensile strength exceeded 70%, whereas the second healing efficiency was above 60%. Moreover, the simple preparation procedure and enhanced mechanical strength facilitate the commercial utilization of recyclable rubber materials, which is crucial for addressing the environmental pollution issue associated with rubber materials.