Synthesis of organic and inorganic hybrid nanoparticles as multifunctional photoinitiator and its application in UV-curable epoxy acrylate-based coating systems

The combination of organic and inorganic components has become an challenging for the generation of new materials with preeminent properties over pure constituents. In the present work, a novel hybrid photoinitiator for free radical photopolymerization, belonging to the thioxanthone derivatives, was obtained via chemical joint between silica and 2-chlorothioxanthone (CTX) under a mild preparation condition. This multifunctional supported photoinitiator (silica-s-CTX) can not only initiate the photopolymerization with higher efficiency than traditional photoinitiator CTX, but also prominently improve the dispersion of nanoparticles in the epoxy acrylates resin which brings to the preeminent mechanical properties of UV-cured coatings. Importantly, the amount of residual-free PIs in silica-s-CTX curing system shows a significant decrease comparing with the filled and unfilled CTX curing system. After endowing the silica nanoparticles with photo-initiated performance, it may offer new scientific and technological opportunities for the preparation of high performance UV-curing coatings.