Study on bifunctional acyldiphenylphosphine oxides photoinitiator for free radical polymerization

Three novel bifunctional acylphosphineoxide compounds containing diallyl amino group were designed and synthesized as photoinitiators for free radical photopolymerization (FRP) of acrylates. Firstly, the photoinitiation properties of DABPOs (DABPO-1, DABPO-2 and DABPO-3), including their UV–vis spectra, the migration after curing and the solubility in monomers, have been studied and compared with commercial photoinitiator 2,4,6- trimethyl(phenyl)diphenyl oxide (TPO).The results show that DABPOs have the red-shift absorption wavelength, higher molar absorption coefficient, lower migration and higher solubility comparing with TPO, and they have higher double bond conversion (DC) in TMPTA monomer than TPO under the exposure of 420 nm. Secondly, DABPOs have been successfully used as co-initiator in H-extraction photocuring system. The results show that diallyl amino acylphosphine oxides are effective bifunctional photoinitiators for photopolymerization under LED irradiation.