Design of α-ketone aryl thioesters photoinitiators for LED photopolymerization

In this study, we designed and synthesized four α-ketone aryl thioesters photoinitiators ( PTEs ) with excellent cytocompatibility for LED photopolymerization using a simple one-step reaction. We investigated the potential photopolymerization initiation mechanisms of PTEs under 405 nm LED irradiation through ultraviolet–visible absorption spectroscopy, high-resolution mass spectroscopy, and electron spin resonance. Our findings revealed that PTEs can effectively initiate the photopolymerization of acrylate monomer tripropylene glycol diacrylate (TPGDA) under either 405 nm or 455 nm LED irradiation, achieving double bond conversions of approximately 80 % or higher after 180 s of irradiation. Remarkably, compared to the commercial photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and benzoyl methacrylate (MBF), PTEs exhibit certain advantage in initiating photopolymerization of triethylene glycol dimethacrylate (TEGDMA) widely used for dental materials under the irradiation of 405 nm. More importantly, MO-PTE has better cytocompatibility compared to TPO and exhibits a great potential in the fields of LED photopolymerization, biomaterials and food packaging.