Novel Ketone Derivatives Involving Triphenylamine Electron‐Donating Group as Low Migration Photoinitiators for Visible Light Radical Polymerization and 3D Printing

Abstract Given the ongoing advancements in photopolymerization technology, there is an imperative need to develop novel free radical photoinitiators (PIs) with long‐wavelength absorbance and low migration. To meet the demand for visible light photopolymerization, four novel ketone derivatives photoinitiators (PHMOs) were synthesized in this study via a one‐step reaction. By constructing the push‐pull structure, the maximum absorption wavelength of the new PIs was red‐shifted to the vicinity of 400 nm, satisfying the requirement of visible excitation. The one‐component photoinitiation effect of PHMOs under visible light was comparable to that of Irgacure 1173, among which the photopolymerisation performance of PHMO‐2 was significantly superior to that of 1173. The photopolymerization effect of the two‐component photoinitiaton system composed by the addition of hydrogen donor was significantly improved. PHMO‐1 was successfully used in 3D printing to produce well‐defined printed products. The photolysis mechanism of PHMOs was investigated by steady‐state photolysis and electron spin resonance test. In addition, PHMOs had good solubility, thermal stability and good biosafety. Attributed to the presence of double bonds, PHMOs had low migration. These excellent properties indicated that PHMOs had desirable potential applications in the field of visible light polymerization.