Construction of a Dual Ionic Network in Natural Rubber with High Self-Healing Efficiency through Anionic Mechanism

Even though considerable efforts have been applied toward self-healing materials, construction of a reversible network in a nonpolar elastomer with a high strength and self-healing behavior is still a considerable challenge. Herein, a novel method to construct a dual ionic network for natural rubber (NR)-based carboxylate ionomers with a high self-healing efficiency through an anionic mechanism is demonstrated. Maleic anhydride (MAH) was grafted with NR by an anionic mechanism to construct the first ionic network, with n -butyllithium as the metallization reagent. Subsequently, zinc dimethacrylate (ZDMA) reacted with the MAH-modified NR, and the second ionic network was constructed. Additionally, scanning electron microscopy analyses showed that the grafting of MAH improved the dispersity of ZDMA in NR, resulting in a stronger reinforcing effect. Compared to the reported ZDMA-based self-healing elastomers, the dual ionic network exhibited a better reinforcing effect with a high self-healing efficiency of 75% in full-cut mode. This concept offers a novel inspiration to design high-performance self-healing elastomers.