Optical and thermal characterization of poly(<i>o</i>-methylaniline) films

Abstract

Poly(<i>o</i>-methylaniline) films have bee deposited by electrochemical polymerization on transparent SnO₂: F coated glass electrodes under galva nostatic conditions. Effect of electrode conductivity, deposition time and applied current on the optical and thermal properties ofthe films have been investigated. The optical absorption spectra of films show a peak at ~800 nm and a shoulder at ~420 nm which is attributed to the transitions of lattice polaron. The shift in absorption wavelengths related to the leucoemeraldine and emraline salt forms of poly(<i>o</i>-methylaniline) as compared with the band positions in pure polyaniline, may be due to steric effect of the methyl substituent. The thermogravimetric analysis shows a three-step decomposition of the polymer corresponding to loss of water molecules, loss of chlorine' and hydrochloric acid, and decomposition and degradation of the polymer backbone respectively.