O-CHLORANIL INITIATED POLYMERIZATION OF PYRROLE IN PRESENCE OF N-VINYLCARBAZOLE AND SOME PROPERTIES OF THE POLYMER

The polymerization of a mixture of N-vinylcarbazole (NVC) and pyrrole (PY) by O-chloranil in toluene yields an insoluble black polymer P(PY- NVC) which exhibits properties distinct from PPY or PNVC. The inclusio n of either monomer moieties in P(PY-NVC) has been endorsed by IR spec troscopy. Kinetics of PPY-OCA homopolymerization and of PY-NVC-OCA cop olymerization have been elucidated. TGA reveals the stability order as PNVC > P(PY-NVC) > PPY. DSC analyses reveal a single inflection for P (PY-NVC) around (198-202 degrees C) and for PPY and PNVC around 180 an d 228 degrees C respectively. PPY exhibits a high dielectric constant (similar to 350) at 10 Hz while P(PY-NVC) or PNVC exhibit values (simi lar to 11) and (similar to 5) respectively-the dielectric constant fal ling consistently with increasing frequency as does the dielectric los s parameter also-suggesting interfacial polarization. P(PY-NVC) shows maximum d.c. conductivity of 3.5 x 10(-6) ohm(-1) cm(-1) depending on [PY]/[NVC] mole ratio. For PPY, the conductivity is in the range (10(- 3)-10(-5))ohm(-1) cm(-1) and the conductivity in all these polymers is dependent on the concentrations of the monomers, O-CA and runs parall el to the trend in conversion.