Force-dependent bond dissociation explains the rate-dependent fracture of vitrimers
Force-dependent bond dissociation explains the rate-dependent fracture of vitrimers
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力依赖性键解离解释了玻璃体的速率依赖性断裂
DOI：
10.1039/d1sm00518a
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Cai, Shengqiang
中科院分区：
文献类型：
--
作者：
Song, Zhaoqiang;Shen, Tong;Vernerey, Franck J.;Cai, Shengqiang
我们通过进行撕裂测试来研究玻璃体的速率依赖性断裂。基于断裂能与玻璃质膜厚度的关系，首次获得了玻璃质膜在裂纹扩展过程中的固有断裂能和体积耗散。固有断裂能强烈依赖于撕裂速度，这种依赖关系可以用Eyring理论很好地解释。相比之下，体积耗散对撕裂速度的依赖性较弱，这与传统粘弹性聚合物的观察结果截然不同。我们将这种弱的速率依赖性归因于动态共价键交换反应的强力敏感性。
We investigate the rate-dependent fracture of vitrimers by conducting a tear test. Based on the relationship between the fracture energy and the thickness of vitrimer films, we, for the first time, obtain the intrinsic fracture energy and bulk dissipation of vitrimers during crack extension. The intrinsic fracture energy strongly depends on tear speed, and such dependence can be well explained by Eyring theory. In contrast, the bulk dissipation only weakly depends on tear speed, which is drastically different from observations on traditional viscoelastic polymers. We ascribe such a weak rate-dependence to the strong force-sensitivity of the exchange reaction of the dynamic covalent bond in the vitrimer.