CATIONIC POLYMERIZATION INITIATED BY ONIUM IONS

4-Chlorobenzene-diazonium, CBD+, N-ethoxyisoquinolinium, EIQ(+), and N -ethoxy-4-cyanopyridinium, ECP+, ions, in the form of hexafluorophosph ate salts, readily initiate in a dark reaction the cationic polymeriza tion of n-butyl vinyl ether, NBVE, isobutyl vinyl ether, IBVE, and N-v inylcarbazole, NVC, in air-saturated dichloromethane solution at room temperature. Hexafluorophosphates of diphenyliodonium, Ph2I+, tripheny lsulphonium, Ph3S+, N-ethoxy-2-methylpyridinium, EMP+, and N-ethoxy-4- phenylpyridinium, EPP+, ions are much less active. They do not initiat e the polymerization spontaneously, but cause a very slow conversion o f these monomers into polymers. All onium salts examined in this work are quite unreactive in initiating the polymerization of cyclohexane o xide, CHO, and alpha-methylstyrene, alpha MSt. However, the polymeriza tion of aerated CHO containing dissolved EIQ(+)PF(6)(-) or CBD+PF6- is readily initiated upon the addition of vinyl ether (IBVE) or N-vinylc arbazole. This result indicates that cationic species generated by the reaction of EIQ(+) or CBD+ ions with IBVE or NVC are capable of initi ating the polymerization of CHO, which itself is unreactive towards th e onium ions under investigation. (C) 1997 Elsevier Science Ltd.