Mechanically strong, thermally stable, and reprocessable poly(dimethylsiloxane) elastomers enabled by dynamic silyl ether linkages

Abstract

Endowing thermosetting materials with reprocessability by incorporating dynamic covalent bonds into the polymer networks is of great realistic significance. However, as most dynamic covalent bonds are thermally and chemically unstable, the application of these materials is limited, especially in high-tech area. Herein, mechanically strong, thermally stable, and reprocessable poly(dimethylsiloxane) (PDMS) elastomers based on silyl ether linkages were developed for the first time. The elastomers have fascinating tensile strength (∼11.0 MPa), which can be simply tuned by adjusting the content of silyl ether linkages. The intrinsic thermal stability of PDMS is retained due to the thermally stable silyl ether linkages, and the initial thermal degradation temperature (T5) is especially increased by ∼ 42 °C. Moreover, the topology rearrangement of the networks can be accomplished through trans-oxyalkylation reactions of silyl ether linkages at elevated temperature with ∼ 78% recovery efficiency of tensile stress. In addition, the material we prepared has good adhesion to a variety of metals. After mixing with multiwalled carbon nanotubes, it can be used as conductive adhesive, showing application potential in the electronics industry.