CONICET | Buscador de Institutos y Recursos Humanos

Photopolymerization has major applications in a multi-billion dollar world-wide market involving coatings, stereolithography, photolithography, adhesives, dental fillings/medical applications, printing, and large-scale composites. In the most general case, radiation (UV or visible) is absorbed by a photoinitiator to form an excited state which is then converted into a reactive species resulting in polymerization of the monomers. Photopolymerization at high initiator concentration is attractive because as initiator concentration increases, polymerization rate typically increases. However, the absorption of light by the initiator causes attenuation of the curing light along the beam direction. Light attenuation results in a gradient of conversion due to the different initiation rates occurring through the irradiation path. Thus, for photocuring products that have larger than millimeter dimensions it is advantageous to use photobleaching initiators in which light absorption by the initiator products is lower than that by the original photoinitiator molecules, thereby allowing more light to pass through the depth. In this context, the study of photobleaching characteristics of photoinitiators used for the polymerization of thick layers is the essential step for a better understanding of the photoinitiation process. In the present work we investigate the photodecomposition of DEABP in solution, its photobleaching behavior, and its performance for the photopolymerization of methacrylate monomers.