Carboxylated nitrile rubber (XNBR) is crosslinked via metal–ligand coordination bond by simple mixing and compounding as an alternate to chemically rich traditional vulcanization route. Basis of the generation of reversible non-covalent crosslinks, in the rubber matrix, is copper (I)–carboxylate metal–ligand interaction that is evidenced by XPS, FTIR, and rheological studies. At low copper content (5 phr), self-healing property is exhibited by the composite while adequate mechanical strength is obtained at higher copper content (20 phr). For 20 phr filled composite (XNBR–Cu20), the tensile strength reaches up to 5.41 ± 0.28 MPa, which is almost 19 times higher than that of pure XNBR (0.29 ± 0.02 MPa). On the other hand, tensile strength is not so high (1.95 ± 0.20 MPa) for composite XNBR–Cu5, however, this one shows the self-healing efficiency of around 75% for the first cycle, 71% for second cycle, and 56% for the third cycle. The positive shift of glass transition temperature (T_g) takes place with the increasing content of copper (I)–carboxylate crosslinking that is caused by the lowering in segmental mobility of the rubber chains. Reversible nature of the metal–ligand coordination, recoverability, and hysteresis in the XNBR–Cu (I) composite are studied by cyclic stress–strain loading. The CuCl content greatly influences the inherent crosslinking nature of the elastomeric network and the ultimate properties of the composites.

中文翻译：

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基于铜 (I)-羧酸盐相互作用在 XNBR 中生成交联网络

羧化丁腈橡胶 (XNBR) 通过简单的混合和复合通过金属-配体配位键交联，作为化学成分丰富的传统硫化路线的替代方法。XPS、FTIR 和流变学研究证明了在橡胶基质中产生可逆非共价交联的基础是铜 (I)–羧酸盐金属–配体相互作用。在低铜含量（5 份）下，复合材料表现出自愈性，而在较高铜含量（20 份）下获得足够的机械强度。对于 20 份填充复合材料 (XNBR–Cu20)，拉伸强度高达 5.41 ± 0.28 MPa，几乎是纯 XNBR (0.29 ± 0.02 MPa) 的 19 倍。另一方面，复合 XNBR–Cu5 的拉伸强度不是那么高 (1.95 ± 0.20 MPa)，但是，这个显示出第一个循环的自愈效率约为 75%，第二个循环为 71%，第三个循环为 56%。玻璃化转变温度正移（T _g ) 随着铜 (I)-羧酸盐交联含量的增加而发生，这是由橡胶链的链段流动性降低引起的。通过循环应力-应变加载研究了 XNBR-Cu (I) 复合材料中金属-配体配位、可恢复性和滞后的可逆性质。CuCl 含量极大地影响了弹性体网络的固有交联性质和复合材料的最终性能。