Conductive polypyrrole composite films by chemical vapor polymerization

Abstract

Polypyrrole composite films were prepared by chemical oxidation of the vapor monomer using two different methods, dissolving and swelling method. In the first method, polymeric matrices were dissolved with FeCl3/THF solution, then casting as film, and exposed to pyrrole vapor. In the second method, polymeric matrices films were swollen in an FeCl3/THF solution and exposed to pyrrole vapor. The composite films were characterized by FT-IR spectroscopy. Their conductivity was determined by Van der Pauw method. In case of the dissolving method, it was assumed that the thickness of the composite film was the thickness of polypyrrole layer. Several factors influenced on conductivity were investigated such as FeCl3 concentration, reaction temperature and reaction time. The conductivity of the polypyrrole composite films increased by decreasing polymerization temperature, decreasing polymerization time and increasing FeCl3 concentration. It was found that polypyrrole composite film obtained by dissolving method, polypyrrole could disperse into matrix better than one obtained by swelling method as revealed by SEM and TEM. Mechanical property, thermal stability and time-decay of the composite films were also investigated