Acid-dopant effects in the formation and properties of polycarbonate-polyaniline composites

• Sulfonic acids affect rate and yield of aniline polymerization in dispersion media.
• In the DBSA (DNNSA) and aniline joint solutions two types of micelles coexist.
• Thermostability of the composites depends on size of the sulfonic acid-dopant anions.
• Compression molding of the PC/PANI-dopant films decreases their conductivity.
• The solution-cast composite films can serve for ppm range gaseous ammonia detection.

The significant effect of various aromatic sulfonic acids on peculiarities of chemical polymerization of aniline in the water dispersion of polycarbonate (PC) powder, morphology and properties of the formed PC-polyaniline composites has been found and studied. In particular, we demonstrate that the rate of the aniline polymerization and polyaniline yield strongly depend on the size and surface activity of the acid-dopant anions. It is found that in the case of the large dopants (e.g. dodecylbenzenesulfonic acid) the composites unexpectedly have the reduced thermostability while the composites with the small dopants (e.g. p-toluenesulfonic acid or 2-naphtalenesulfonic acid) display the enhanced thermal stability as compared with the pure PC. We confirm that the acid-dopant nature affects the thermal stability of conductivity of the compression molded composite films. The solution-cast composite films have the dopant dependent sensitivity to gaseous ammonia in a wide ppm range of its concentrations.