INITIATION OF CATIONIC POLYMERIZATION VIA OXIDATION OF FREE-RADICALS USING PYRIDINIUM SALTS


BOTTCHER A., HASEBE K., HIZAL G. , YAGCI Y. , STELLBERG P., SCHNABEL W.

POLYMER, vol.32, no.12, pp.2289-2293, 1991 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 12
  • Publication Date: 1991
  • Doi Number: 10.1016/0032-3861(91)90061-m
  • Title of Journal : POLYMER
  • Page Numbers: pp.2289-2293

Abstract

Pyridinium ions of appropriate reduction potential E1/2red are capable of oxidizing carbon-centred free radicals to carbocations that can initiate the polymerization of various compounds. 1-Ethoxy-2-methyl pyridinium ions of E1/2red = -0.7 V were found to react with free radicals generated by (a) photolysis or (b) thermolysis of various compounds. Radical generation was achieved in case (a) with benzoinmethylether, diphenyl-2,4,6-trimethylbenzoylphosphine oxide or benzophenone/tetrahydrofuran (BP/THF) and in case (b) with phenylazotriphenylmethane, BP/THF, benzoylperoxide/THF or 2,2-azobisisobutyronitrile/THF. The following monomers were polymerized: 1,2-epoxycyclohexane (cyclohexene oxide) and n-butylvinyl ether.