REDOX CATIONIC POLYMERIZATION - THE DIARYLIODONIUM SALT-ASCORBATE REDOX COUPLE

This paper describes the development and use of the diaryliodonium salt/ascorbate redox couple in the polymerization of several types of cationically polymerizable monomers. It is shown that strong Bronsted acids are produced on reduction of diaryliodonium salts containing anions of the type BF** minus //4, AsF** minus //6, PF** minus //6, SbF** minus //6 by ascorbic acid and its derivatives in the presence of catalytic amounts of copper salts. The cationic polymerizations of cyclohexene oxide, tetrahydrofuran, and s-trioxane were studied using the diaryliodonium salt/ascorbate redox couple. Extensive experimental data are presented which demonstrate that the diaryliodonium salt/ascorbate redox couples provide a new method of initiating the cationic polymerization of a wide variety of vinyl and heterocyclic monomers.