Meta-Terphenyl Derivative/Iodonium Salt/9H-Carbazole-9-ethanol Photoinitiating Systems for Free Radical Promoted Cationic Polymerization upon Visible Lights

In the present paper, new photoinitiators based on the meta‐terphenyl scaffold in combination with an iodonium salt and 9H‐carbazole‐9‐ethanol (CARET) are proposed for the free radical promoted cationic polymerization of epoxides upon visible light exposure using light emitting diodes at 405, 455, and 470 nm. Remarkably, a new high performance additive (i.e., CARET) is proposed here for cationic polymerizations. CARET shows some important advantages compared to other reported additives such as N‐vinylcarbazole or benzyl alcohol used as references. Excellent polymerization initiating abilities are found and a full picture of the involved chemical mechanisms is provided. A new high performance additive (i.e., 9H‐carbazole‐9‐ethanol (CARET)) is proposed here for cationic polymerizations in combination with new photoinitiators based on the meta‐terphenyl scaffold. CARET shows some important advantages compared to other reported additives used as references.