Innovative Synthesis of Photo‐Responsive, Self‐Healing Silicone Elastomers with Enhanced Mechanical Properties and Thermal Stability

Abstract

AbstractPhoto‐responsive materials have garnered significant interest for their ability to react to non‐contact stimuli, though achieving self‐healing under gentle conditions remains an elusive goal. In this research, an innovative and straightforward approach for synthesizing silicone elastomers is proposed that not only self‐heal at room temperature but also possess unique photochromic properties and adjustable mechanical strength, along with being both transparent and reprocessable. Initially, aldehyde‐bifunctional dithiophene‐ethylene molecules with dialdehyde groups (DTEM) and isocyanurate (IPDI) is introduced into the aminopropyl‐terminated polydimethylsiloxane (H2N‐PDMS‐NH2) matrix. Subsequently, palladium is incorporated to enhance coordination within the matrix. These silicone elastomers transition to a blue state under 254 nm UV light and revert to transparency under 580 nm light. Remarkably, they demonstrate excellent thermal stability at temperatures up to 100 °C and show superior fatigue resistance. The optical switching capabilities of the silicone elastomers significantly affect both their mechanical characteristics and self‐healing abilities. Notably, the PDMS‐DTEM‐IPDI‐@Pd silicone elastomer, featuring closed‐loop photo‐switching molecules, exhibits a fracture toughness that is 1.3 times greater and a room temperature self‐healing efficiency 1.4 times higher than its open‐loop counterparts. This novel photo‐responsive silicone elastomer offers promising potential for applications in data writing and erasure, UV protective coatings, and micro‐trace development.