The mechanism of initiation in the free radical polymerization of N-vinylcarbazole and N-vinylpyrrolidone

The reactions of N-vinylcarbazole and of N-vinylpyrrolidone with benzoyl peroxide and with di-t-butyl peroxalate in the presence of the nitroxide scavenger 1,1,3,3-tetramethyl-1,3-dihydroisoindol-2-yloxyl are reported. Use of di-t-butyl peroxalate leads to the expected radical intermediates which are efficiently scavenged by the nitroxide. When benzoyl peroxide is used as initiator however, both ionic and radical processes are involved. The importance of electron-transfer processes is discussed.