Abstract Conventional crosslinking endows rubbers with excellent mechanical properties, at the same time, turn them to be thermosets with the impossibility of recycling and self-healing. From the perspective of sustainable development of material, it is crucial and meaningful to integrate these charming properties into crosslinked commercial rubbers. In this paper, we prepared a recyclable and healable epoxidized natural rubber (ENR)/citric acid-modified bentonite (CABt) composite. CABt with numerous carboxyls on surface served as cross-linker to covalently crosslink ENR through exchangeable β-hydroxyl ester linkages, as well as efficient reinforcer for ENR. Because of the transesterification reactions of β-hydroxyl ester linkages between CABt and ENR, ENR/CABt composites could alter the network topology at elevated temperature. Meanwhile, the low crosslink degree of network and inherent stickiness of ENR matrix facilitated chain diffusion and transesterification reactions of β-hydroxyl ester linkages, which made ENR/CABt composites recycled and healed. Thus, we envision that our work would open up new avenues to design more crosslinked rubber composites showing recyclable, healable and adaptable abilities.

中文翻译：

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可回收和可热修复的环氧化天然橡胶/膨润土复合材料

摘要 常规交联赋予橡胶优异的力学性能，同时使其成为热固性材料，无法回收利用和自愈。从材料的可持续发展的角度来看，将这些迷人的特性融入交联的商业橡胶中是至关重要的和有意义的。在本文中，我们制备了一种可回收和可修复的环氧化天然橡胶（ENR）/柠檬酸改性膨润土（CABt）复合材料。表面具有大量羧基的 CABt 作为交联剂通过可交换的 β-羟基酯键共价交联 ENR，同时也是 ENR 的有效增强剂。由于 CABt 和 ENR 之间 β-羟基酯键的酯交换反应，ENR/CABt 复合材料可以在升高的温度下改变网络拓扑。同时，ENR基体的低交联度和固有的粘性促进了β-羟基酯键的链扩散和酯交换反应，使ENR/CABt复合材料回收和愈合。因此，我们设想我们的工作将开辟新的途径来设计更多交联的橡胶复合材料，显示出可回收、可修复和适应性强的能力。