A new carbazolyl-basedacylphosphine oxide photoinitiator with high performance and low migration

In order to obtain a new photoinitiator with high efficiency, low migration, and high solubility in acrylate monomers, a new compound named 9-allyl-9H-carbazol-3-yldipenylphosphine oxide (ALPO) was designed and synthesized. Compared to 9-ethyl-9H-carbazol-3-yldipenylphosphine oxide, the double bond conversion (DC) and solubility of ALPO in acrylic monomers were greatly improved, and the migration rate was greatly reduced after replacing the ethyl group in the molecule with an allyl group. Compared with (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO), which was widely used commercially, ALPO had a higher DC and lower migration rate. This means that ALPO may be able to replace TPO in the light curing field.