Electroinitiated Polymerizations

Mengoli, G. Feasibility of Polymer Rim Coating Through Electroinitiated Polymerization in Aqueous Medium. Vol. 33, pp. 1-31. 

Electrolytic or electroinitiated polymerization involves initiation by cations formed via electrolysis of some component of the reaction system (monomer, solvent, electrolyte, or other deliberately added substance) [Cerrai et al., 1976, 1979 Funt et al., 1976 Oberrauch et al.,... 

Some electroinitiated polymerizations proceed via monomer radical-cations (VII) formed by electron transfer... 

Electroinitiated polymerization proceeds by direct electron addition to monomer to generate the monomer anion-radical, although initiation in some systems may involve the formation of an anionic species by electrolytic reaction of some component of the reaction system (often the electrolyte) [Olaj, 1987]. 

We condude this section by stating that the field-accelerating effect on copolymerizations and the change of the monomer reactivity ratio with the field can be accounted for in terms of the interpretation proposed for cationic homopolymerizations, namely the field-facilitated dissociation of the growing chain ends. We should note that the observed field influence on the copolymerization excludes the possibility of the electroinitiated polymerization mechanism. 

Besides the field influence on the monomer reactivity ratio mentioned in the previous sections, living anionic systems present strong evidence against the electroinitiated polymerization mechanism. First of all, the experimental fact, that the apparent rate constant of propagation was increased by the presence of an electric field, rules out a possibility that the observed field-accelerating effect resulted only from the initiation reaction enhanced by the field. The finding that the field had no influence on the dependences of the polymerization rate on monomer and initiater concentrations, but did influence the rate constant, implies that the reaction mechanism was unaltered by the application of the field. These results confirm our very low opinion of the electroinitiated polymerization mechanism. 

The azo (V-oxide (75) was reduced in DMF to the dianion of azopyridine.118 Electroinitiated polymerization of a 2-azopyridine gave a polymer useful for modifying electrode surfaces.119 The only other reports of azopyridine electrochemistry involve voltammetry.120... 

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