Vitrimers with dynamic covalent bonds are sustainable alternatives for traditional thermosetting polymers. The variations of building block alter the properties of vitrimers, but obstruct detailed structure–property correlations. Besides, a recognizable crosslinking reaction is responsible for the network structures of vitrimers. Herein, we investigated the effects of building block variations (i.e., the content of crosslinker, and the type and molar mass of polymer matrix) on the crosslinking kinetics, as well as on the static and dynamic properties using polyether-based vinylogous urethane vitrimers as model system. The kinetics of crosslinking tracked by in situ FTIR provides an insightful understanding on the vitrimer yield and formation rate under conditions. And the apparent rate coefficient (k) was linearly correlated to the crosslinking density (ν_e) in case of different polymer matrixes being used. In addition, based on the classical theoretical models we also realized the correlations between the static property (i.e., glass transition temperature, T_g) and ν_e, as well as the dynamic property (i.e., topology freezing temperature, T_v) and ν_e. T_g has been found to be exclusively positively related to ν_e, while T_v is jointly determined by ν_e and the content of free amine. This strategy to establish reaction–structure–property relationship bridged by the crosslinking density will guide the preparation of novel, tailor-made sustainable polymeric materials.

中文翻译：

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绘制聚醚基乙烯基聚氨酯玻璃体中的交联反应-结构-性能关系

具有动态共价键的 Vitrimers 是传统热固性聚合物的可持续替代品。构建块的变化改变了玻璃体的性质，但阻碍了详细的结构-性质相关性。此外，可识别的交联反应是造成玻璃体网络结构的原因。在此，我们研究了结构单元变化（即交联剂的含量，以及聚合物基质的类型和摩尔质量）对交联动力学以及使用聚醚基乙烯基聚氨酯玻璃体作为静态和动态性能的影响。模型系统。原位FTIR跟踪的交联动力学提供了对特定条件下 vitrimer 产率和形成速率的深刻理解。和表观速率系数 (在使用不同的聚合物基质的情况下，k )_与交联密度 ( νe ) 呈线性相关。此外，基于经典理论模型，我们还实现了静态特性（即玻璃化转变温度，T _g）与ν _e之间的相关性，以及动态特性（即拓扑冻结温度，T _v）与ν之间的相关性。 _e . 已发现T _g与ν _e完全正相关，而T _v由ν _{e共同决定}和游离胺的含量。这种通过交联密度建立反应-结构-性能关系的策略将指导新型、量身定制的可持续聚合物材料的制备。