Resumo

REYNA, J.M.; AGUILAR, M.  e  ROQUERO, P.. Synthesis of Poly-N-Vinylcarbazole by Direct and Indirect Electrolysis. Port. Electrochim. Acta [online]. 2005, vol.23, n.1, pp.77-87. ISSN 0872-1904.

Poly-N-vinylcarbazole (PNVCz) can be obtained by two different ways: when the reaction takes place through the vinyl group of the monomer, a white, linear-chain polymer, with interesting photoconducting properties, is obtained. When the polymerization occurs through the aromatic rings, the main product is a green, cross-linked polymer. Polymerization of N-vinylcarbazole (NVC) is possible by electrochemical oxidation. Direct anodic oxidation leads mainly to the green form of the polymer. Protons released from the initial oxidation of the aromatic rings, induce the polymerization through the vinyl group. Indirect electrolysis, making use of an intermediate to achieve oxidation of the monomer, is also possible. In particular, the electrochemical generation of Ce(IV) allows to increase selectivity towards the linear-chain polymer, and can be the basis for the development of a new process, involving the anodic oxidation, in aqueous phase, of Ce(III) to Ce(IV), which will activate the polymerization reaction through the vinyl group. This work presents results from initial characterization, by cyclic voltammetry, of the reacting system. The anodic polymerization of the monomer (NVC) was carried out in acetonitrile, using sodium perchlorate as supporting electrolyte, in the presence and in the absence of cerium salts. The voltammetric response of Ce(III) in aqueous phase, as a possible initiator for the polymerization, is also presented.

Palavras-chave : poly-N-vinylcarbazole; direct and indirect electrolysis; cerium intermediate.

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