A Robust and Thermally Stable Poly(dimethylsiloxane) Elastomer with Reprocessability Based on Dynamic Silyl Ether Linkages.

Polysiloxane elastomers have drawn considerable attention especially benefitting from their excellent thermal stability. Nevertheless, as commercial polysiloxane elastomers possess permanently crosslinked networks, they are generally unrecyclable and thus detrimental to environment at the end of service life. Although introducing reversible covalent bonds into polysiloxane networks can achieve reprocessability, the thermal stability is declined as many reversible bonds are thermally unstable. Herein, in order to combine the desirable attributes of reprocessability and thermal stability, polydimethylsiloxane elastomers are prepared by incorporating thermally stable silyl ether linkages into networks as dynamic crosslinks for the first time. The elastomer exhibits outstanding mechanical properties, excellent solvent resistance, and even largely enhanced thermal stability (the initial degradation temperature is increased by 33 °C). Moreover, the elastomer is able to reshuffle the network topology through trans‐oxyalkylation reactions of silyl ethers, thus capable of distinguished reprocessability at high temperatures. In a word, this work provides a facile strategy for integrating reprocessability into thermosetting materials without sacrificing their thermal stability. [ABSTRACT FROM AUTHOR]