Polymerizations initiated by boron fluoride etherate—III. The role of the electrodic processes in polymerizations under electric field

✍ Scribed by P. Cerrai; G. Guerra; L. Nucci; M. Tricoli

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 516 KB
• Volume: 21
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(85)90133-8

✦ Synopsis

The electrodic processes occurring when a d.c. electric field is applied to the polymerization of vinyl-aromatic monomers initiated by boron trifluoride etherate in 1,2-dichloroethane solution have been investigated. Retardation of the polymerization rate by the field, sometimes overcoming the well known field acceleration, has been attributed to electrochemical reactions at the cathode. Linear and cyclic voltammetries on the various reactants show that the field acceleration is due to anodic oxidation of the monomer, that boron trifluoride etherate is easily reducible and that the electrolysis of water and of its complexes with BFs is hardly relevant. Electrolyses of solutions of the etherate at its reduction potential, as well as the use of the electrolysed solutions to initiate anethole polymerization, confirm the cathodic formation of inhibiting species, among which chloride ion has been identified. An ECE reduction mechanism of boron trifluoride etherate consistent with the experimental results is proposed. The non-electrolytic component of the field acceleration observed by other authors and by us in polymerizations carried out in cells with external electrodes is discussed.