Low migration type I photoinitiators of radical polymerisation

Two low migration acylphosphine oxide photoinitiators (APO and DAPO) containing unsaturated Cdouble bondC double bonds have been designed and synthesized for free radical polymerization. The properties and performances of APO and DAPO in the free radical polymerisation of trimethylolpropane triacrylate (TMPTA) were evaluated and compared with the commercial photoinitiator 2,4,6-trimethyl(phenyl) diphenyl oxide (TPO).

Possibility for industrial application

The results show that DAPO exhibited the best double bond conversion (DC) of TMPTA in the photoinitiators tested under the same reaction conditions. The migration ratio of APO and DAPO was 2/3 and 1/3 of that of TPO respectively indicating lower migration than the conventional photoinitiator, and the solubility of DAPO in monomers was close to that of TPO, which provided the possibility for the industrial application of DAPO.

The study has been published in Progress in Organic Coatings, Volume 168, July 2022.