Chemical Synthesis and Characterization of Polyaniline Derivatives: Substituent Effect on Solubility and Conductivity

Polyanilines have different macroscopic properties according to the substituent incorporated into their monomers. Being conducting polymers, one of these properties is conductivity, which may increase or decrease depending on the substituent and its position in the chain. This work is focused on the modification of aniline monomers, which characteristics will vary, enabling thus the effect of the substituent on the respective polymer to be studied. For this purpose monomers substituted with methoxy and bromine, which are commercially available, and thiophenes were prepared using Suzuki and Ullman reactions. It was found that all polymers have conductivities of the order of 10 -6 Scm -1 or less. This demonstrated the performed substitutions had a negative effect on conductivity (although would facilitate their use in solar cells) as compared to aniline (PANI). These modifications also improve the solubility of the respective polymers, as most were more soluble than PANI.