Reversible Dynamic Behavior of Condensation‐Cured Silicone Elastomers Caused by a Catalyst

Abstract

This study demonstrates that dibutyltin‐dilaurate (DBTL), commonly used to catalyze condensation‐cured silicone elastomers, causes dynamic behavior in the silicone network, which is attributed to the catalyst finding a way to become part of the elastomer network. Furthermore, it establishes that by choosing an appropriate silanol‐terminated polydimethylsiloxane (HO‐PDMS‐OH) chain length, the catalyst causes the gelation of the system without a cross‐linker. To the best of authors' knowledge, this is the first time that the DBTL catalyst is shown, apart from the catalytic effect, to have the ability to act as a cross‐linker.

Oligosiloxane-Based Epoxy Vitrimers: Adaptable Thermosetting Networks with Dual Dynamic Bonds

“…The silanolate groups can then exchange with siloxanes in a substitution-like reaction. These approaches have proved useful in both elastomers and thermosets. , Recently, there has been work on direct silyl ether metathesis using catalysts, Bronsted or Lewis acids, or the introduction of free hydroxyls into the network. , Du Prez and co-workers have developed siloxane-containing vitrimers with very fast dynamics (below 10 s) in the presence of basic catalysts. , Due to the flexibility of the siloxane units, the prepared resins exhibited low viscosities, which offers significant advantages for fiber-reinforced polymer composite manufacturing. Additionally, it has been shown that the incorporation of siloxane groups into reprocessable networks improves the dielectric properties and ductility. , …”