Conductive polymers,
such as polypyrrole and polyaniline, have
been extensively studied for their notable intrinsic electronic and
ionic conductivities, rendering them suitable for a range of diverse
applications. In this study, in situ chemical polymerization was employed
to coat extruded PLA films with PPy and PANi. Morphological analysis
reveals a uniform and compact deposition of both polyaniline and polypyrrole
after polymerization periods of 3 and 1 h, respectively. Furthermore,
the PLA–PANi-3h and PLA–PPy-1h composites exhibited
the highest electrical conductivity, with values of 0.042 and 0.022
S cm–1, respectively. These findings were in agreement
with the XPS results, as the polyaniline-coated film showed a higher
proportion of charge carriers compared to the polypyrrole composite.
The elastic modulus of the coated films showed an increase compared
with that of pure PLA films. Additionally, the inflection temperatures
for the PLA–PANi-3h and PLA–PPy-1h composites were 368.7
and 367.2 °C, respectively, while for pure PLA, it reached 341.47
°C. This improvement in mechanical and thermal properties revealed
the effective interfacial adhesion between the PLA matrix and the
conducting polymer. Therefore, this work demonstrates that coating
biopolymeric matrices with PANi or PPy enables the production of functional
and environmentally friendly conductive materials suitable for potential
use in the removal of heavy metals in water treatment.