Zinc-based metal complexes as new photocatalysts in polymerization initiating systems

Zinc-based metal complexes (ZnC) are proposed as original photoinitiators in multi-component systems for the formation of free radicals under visible light irradiation. The ZnC/iodonium salt/additive three-component systems (where the additive can be a silane or a divinyl ether) present an excellent ability to promote either the free radical polymerization of an acrylate, the cationic polymerization of a divinyl ether and the polymerization of acrylate/vinyl ether blends under very soft irradiations (e.g. halogen lamp irradiation) or laser diodes (457 or 532 nm) exposure. The mechanisms are investigated by photolysis, luminescence and ESR experiments.