Photopolymerization of Cationic Monomers and Acrylate/Divinylether Blends under Visible Light Using Pyrromethene Dyes

New photoinitiating systems based on boron-dipyrromethene dye (bodipy)/iodonium salt and optionally tris(trimethylsilyl)silane are proposed for the polymerization of divinylether and epoxy monomers upon visible-light exposure. The presence of the silane increases the epoxide rate of polymerization and conversion. Using acrylate/vinyl ether blends, the synthesis of cross-linked polymer networks (possessing two T-g values: -11 and 111 degrees C) is also successfully achieved through concomitant cationic and radical polymerization pathways. The chemical mechanisms associated with these initiating systems are investigated by steady-state photolysis and ESR experiments.