Synthesis and Photocuring Properties of One-component Polymerizable Thioxanthone-based Photoinitiators with High Migration Stability

The development of high-performance UV-LED excited photoinitiators (PIs) is one of the current research hot spots in the field of photopolymerization. Thioxanthone (TX) derivatives have good UV-visible absorption ability under UV excitation. In this article, four novel thioxanthone derivatives were designed and synthesized as one-component polymerizable photoinitiators, and their structures were confirmed by FT-IR and 1H NMR. Their photophysical/photochemical, kinetic and migration stability were investigated experimentally by UV-vis spectrophotometer and Fourier transform infrared spectrometer. The photolysis and photoinitiation mechanisms of four initiators were elucidated. Comparison of the results for the TX system showed that these TX derivatives are highly efficient one-component polymerizable PIs with high migration stability, which has the potential to be used in UV curing systems, especially for food packaging and biomedical applications.