Substituted polyaniline-polypropylene film composites: preparation and properties

Electrically conductive polymer composites containing polyaniline and substituted polyanilines were prepared by one-step chemical oxidation polymerization. Substituted anilines used were o-toluidine and o-chloroaniline. The matrix polymer was a polypropylene (PP) microporous film which was prepared by a biaxial stretching technique. The structure of the conducting polymers in composites was characterized by IR, UV-Vis and X-ray photoelectron spectra. The conductivity of these three kinds of composites was decided mainly by the conductivity of the corresponding conducting polymers, and decreased in the following order: polyaniline/polypropylene, poly(o-toluidine)/polypropylene and poly(o-chloroaniline)/polypropylene. Their conductivities were in the same order of magnitude as those of the corresponding pure polyaniline family of polymers, which were synthesized by the conventional polymerization method of chemical oxidation. The conductivity of the composite was influenced by the reaction conditions, including the reaction temperature, concentrations of monomer and oxidant, reaction time, etc. Different surface morphology was observed on the two sides of the composites. The mechanical properties of the composites were quite similar to those of the PP microporous film. Their elongation at break was much larger than that of the pure polyaniline.