Abstract
A systematic structural and thermal characterization of conducting polypyrrole doped with BF4 − was performed using a direct insertion probe pyrolysis mass spectrometry technique. The effect of dopant concentration on the structure and stability was investigated not only by analyzing samples with different doping levels, but also analyzing the dedoped polypyrrole sample. To get a better understanding, the changes in structure and stability upon overoxidation and thermal aging were also studied. During pyrolysis, mainly three thermal decomposition stages were observed. The first stage below 100°C was associated with evolution of adsorbed water, the solvent acetonitrile, tetrabutylammonium ion, and unreacted pyrrole. The dopant peaks such as BF3, BF2, and BF were recorded at moderate temperatures around 250°C, whereas, polypyrrole peaks showed up in the last stage above which is 300°C. It has been observed that at high BF4 − concentrations aromatic structure was enhanced contrary to what was observed for p-toluene sulfonic acid doped polypyrrole in our previous studies.
ACKNOWLEDGMENT
This work is partially supported by TUBITAK Research Fund TBAG-1691.