A novel acyl phosphine compound as difunctional photoinitiator for free radical polymerization

In order to use the visible light for light curing, a new compound named 4-diethylaminobenzoyldipenylphosphine oxide (DEAPO) was designed and synthesized. Firstly, DEAPO shows good performance as the cleavage photoinitiator in the photopolymerization of trimethylolpropane triacrylate (TMPTA). The double bond conversion obtained with DEAPO system was even higher than the widely used acyl phosphine photoinitiator (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO). With the same initial quality, the migration of DEAPO was much lower than TPO. Secondly, DEAPO was successfully used as coinitiator in the H-abstraction type photoinitiation system because of the diethyl amino group. Results mean that the novel acylphosphine oxide DEAPO was an efficient difunctional photoinitiator.