Electrochemical preparation and physicochemical study of polymers obtained from carbazole and N-((methoxycarbonyl)methyl)carbazole

The polymerization of carbazole (Cz) and N-((methoxycarbonyl)methyl)carbazole (CzE) was carried out by electrochemical oxidation in acetonitrile solution. Different feed ratios of monomers were used to deposit polymer thin films with different compositions and study the influence of the ratio of monomers on the electrochemical, morphological, mechanical and adhesive properties of the polymer films. The electrochemical oxidation led to the deposition of a polymer film whatever the feed ratio but the thickness of the film increased with the portion of unmodified carbazole. On the contrary, the composition of the monomer mixture had a low influence on the AFM adhesion forces between the AFM tip and the polymer film. Depending on the feed monomer ratio, the morphology was either globular or columnar (when the portion of CzE was comprised between 10% and 70%). The stiffness of the polymer films was also found to be strongly dependent on the feed ratio since it varied from 2 to 115 GPa depending on the monomer ratio. The polymer films prepared from the ratios 90:10 and 70:30 in Cz:CzE monomer solutions were found to be the most interesting ones since they led to thick and conducting polymer films with a good adhesion and a low stiffness. Moreover, these coatings were uniform and exhibited an original columnar structure.