Strategies to develop α-aminoketone derivatives photoinitiators with low migration ability for UV–vis LED photopolymerization

Abstract

In this work, a polymerizable vinyl sulfide modified 907 derivative (PI-1) and four macromolecular photoinitiators (PI-2–5) based on PI-1 were designed and synthesized to realize low migration together with a high photoactivity. The structures of these photoinitiators were confirmed by 1H NMR, 13C NMR, HRMS, and GPC analysis. Time-resolved 1H NMR, photolysis, and quantum yield experiments illustrated that the rate of the photogenerated free radicals from PI-1 was slower than that of Irgacure 907. The macromolecular strategies of PI-1 successfully improved the photoactivity of PI-2–5 compared with PI-1. Moreover, PI-4 prepared by copolymerization between PI-1 and methyl methacrylate demonstrated a higher quantum yield of free radical generation than Irgacure 907 and better photoinitiating performance as evaluated by bulk and solution photopolymerization. Furthermore, the migration stabilities of these photoinitiators in the photocured films were better than those of 907. The high efficiency and low migration of the above photoinitiators make them potential applications in food packaging and biological materials.