Inspired by natural materials, sacrificial bonds have been successfully applied in the design of flexible shape memory polymers (SMPs). However, thermal oxidative stability of these SMPs is worth to be concerned because it is inevitable for the applications. Herein, model shape memory rubber composite was prepared by adding ZnCl₂ and sulfur into nitrile butadiene rubber (NBR). Dual crosslinking networks with sacrificial bonds, composed of Zn²⁺-CN coordination bonds, was constructed in NBR composite, which endowed itself a good shape memory property in air, water and even oil. Through 20-day thermal oxidation at 100 °C, Zn²⁺-CN coordination bonds were partially dissociated and ZnCl₂ agglomerations were gradually dissolved into rubber matrix. The growth of covalent crosslinking density accompanied with chains scission during aging. Excessive growth in covalent crosslinking density and the loss of coordination bonds induced a rapid ductile-brittle transition of NBR composite in mechanical tests. Ruptured chains developed an additional relaxation with Zn²⁺ ions to broaden glassy transition of rubber matrix through aging, which increased the shape fixing ratio of NBR composite and descended its recovery ratio. Moreover, the shape recovery processes were obviously slowed down owing to aging. These novel findings reveal that thermal-oxidative aging processes change the architecture of dual crosslinking networks and affect shape memory behaviors of modeled rubbers which are practically useful for the lifetime of their products.

受天然材料的启发，牺牲性粘合已成功应用于柔性形状记忆聚合物（SMP）的设计中。但是，这些SMP的热氧化稳定性值得关注，因为它对于应用是不可避免的。在此，通过将ZnCl ₂和硫添加到丁腈橡胶（NBR）中来制备模型形状记忆橡胶复合材料。在NBR复合材料中构建了具有Zn ²⁺ -CN配位键的牺牲键的双交联网络，使其在空气，水甚至油中具有良好的形状记忆性能。通过在100°C下进行20天的热氧化，Zn ²⁺ -CN配位键部分解离并且ZnCl ₂团聚逐渐溶解在橡胶基质中。共价交联密度的增长伴随着老化过程中的断链。在机械测试中，共价交联密度的过度增长和配位键的丧失引起了NBR复合材料的快速延性-脆性转变。破裂的链与Zn ²⁺一起产生了额外的弛豫离子通过老化来加宽橡胶基质的玻璃态转变，从而增加了NBR复合材料的形状固定率，并降低了其回收率。此外，由于老化，形状恢复过程明显减慢了。这些新颖的发现表明，热氧化老化过程改变了双交联网络的结构并影响了建模橡胶的形状记忆行为，这对于其产品的使用寿命实际上是有用的。