Mapping crosslinking reaction–structure–property relationship in polyether‐based vinylogous urethane vitrimers

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 (νe) 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, Tg) and νe, as well as the dynamic property (i.e., topology freezing temperature, Tv) and νe. Tg has been found to be exclusively positively related to νe, while Tv is jointly determined by νe 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.