Electro-initiated cationic polymerizations—III: Polymerization of anethole in the presence of tetra-alkylammonium perchlorates

The electro-polymerization of trans-anethole in 1,2-dichloroethane solution with tetraethyland tetrabutylammonium perchlorates as supporting electrolytes was studied: the dependences of polymerization rates and molecular weight on some experimental parameters were determined.To investigate the electrolytic formation of initiating species, the anolyte from the electrolysis of the supporting salt in the absence of monomer was examined; the presence of electrolytically produced perchloric acid was ascertained unequivocally. However, owing to the polarographic behaviour of anethole, which shows an oxidation wave at lower anodic potential than the solvent—salt couple, it was not possible to postulate any reaction mechanism based on a single initiation reaction.The fact that the polymerizations were carried out without control of the anodic potential and some of the kinetic results indicate that two parallel initiation reactions (direct monomer oxidation and protonation by electrolytically formed perchloric acid) can occur.