Three novel addition-fragmentation agents (AFA), namely allyl-N,N-dimethylanilinium (ADA), methylallyl-N,N-dimethylanilinium (MADA), and ethoxycarbonylallyl-N,N-dimethylanilinium (EADA) salts with a hexafluoroantimonate counteranion were synthesized and characterized. Their capability to act as initiator and co-initiator for the cationic polymerization of cyclohexene oxide (CHO) was examined. Both the thermally latent effectiveness and the photochemically latent effectiveness of these salts, in promoting polymerization of CHO at 70 degreesC and lambda < 300 nm, respectively, were investigated. The accelerating effect of thermal and photochemical radical sources were also demonstrated. The contribution of electron transfer and addition-fragmentation mechanisms were discussed. Photoinitiated polymerization of some other monomers such as n-butyl vinyl ether (BVE), isobutyl vinyl ether and N-vinylearbazole (NVC) at lambda greater than or equal to 350 nm using benzoin and an EADA initiating system was also performed.