Microwave‐assisted alcoholysis of silicone rubber waste with geraniol for effective elastomer damping

The first step in the mainstream end‐of‐life management of discarded silicone‐rubber‐based composite insulators involves grinding and modification of them into fine silicone rubber powders (SRPs). However, significant knowledge gaps have prevented researchers from developing direct efficient surface treatments for SRPs that do not involve time‐consuming and multi‐step processes. Herein, we report a straightforward method for the efficient modification of discarded SRPs through a microwave‐assisted alcoholysis process. Specifically, the siloxane moieties of the SRPs were cleaved using nucleophilic geraniol as a modifier, thereby facilitating the introduction of abundant alkoxysilyl groups on SRPs surface. During sulfur crosslinking, the intrachain vinyl functionalities of the modified SRPs co‐crosslinked with the rubber matrix via sulfur bridges, thereby improving the dispersion state of the SRPs and the interfacial adhesion between the SRPs and the rubber matrix. Accordingly, even for a high SRP loading (200 phr, parts per hundreds of gum), the mechanical performance of the resulting systems, and in particular the tensile strength and extensibility were significantly higher than those of the rubber matrix. Moreover, the interfacial adhesion of the resulting systems was improved, and the resulting systems presented remarkable damping performance (tan δ ≥ 0.3) over a broad temperature range (≥80°C).