Silicone-Modified Flavonols for Organosilicon Photopolymerization

Organosilicon polymers exhibit excellent biocompatibility and stable chemical properties, and the use of photopolymerization in synthesizing silicone polymers is increasing due to its environmental and energy-saving benefits. However, most photoinitiators cannot be dissolved in a sufficient quantity in silicone prepolymers and have wavelengths that do not align with eco-friendly LED light sources, posing challenges in the photopolymerization of silicone prepolymers. This study focuses on the synthesis of two flavonol photoinitiators, HF-MDT and HF-MTQ, incorporating poly(sesquisiloxanes). The results for photopolymerization demonstrated that they have good compatibility with methacrylate-containing poly(sesquicarbazone) prepolymer, enabling the initiation of photopolymerization under 365 or 460 nm LEDs when combined with co-initiators triethanolamine/iodonium salt (TEOA/ONI). Films cured with HF-MDT and HF-MTQ exhibited enhanced migratory stability and hydrophilicity, making these photoinitiators suitable for various applications, such as silicone coating manufacturing, medical devices, and food packaging. Through fluorescence burst experiments, cyclic voltammetry experiments, and electron paramagnetic resonance experiments, the interaction mechanisms of flavonol photoinitiators with co-initiators were elucidated, providing insights into their photoinitiation activities under LED light sources.