A Robust, Thermally Stable, and Efficiently Reprocessable Poly(dimethylsiloxane) Elastomers Based on Activated Dynamic Silyl Ether Linkages by Neighboring Groups

Dynamic bonds are usually used to endow thermoset materials with excellent reprocessability. Nevertheless, this strategy sacrifices the thermal stability in most instances. In recent years, the dynamic silyl ether (Si  O  R) has attracted great attention due to its excellent thermal stability. However, the reprocessability of thermoset materials based on it is far from satisfactory because of the inactive dynamic exchange reaction. Herein, a species of activated silyl ether with neighboring groups is identified via small-molecule model reaction and the corresponding activation energy is calculated by reaction kinetics for the first time. Based on the activated silyl ether linkages, the poly(dimethylsiloxane) elastomers with high mechanical strength, effective reprocessability, and thermal stability are further designed and prepared. In a word, this work fills a research gap about the effect of neighboring groups on the dynamic characteristic of silyl ether and provides a theoretical basis for the construction of activated silyl ether linkages, endowing the materials with thermal stability and efficient reprocessability.