Degradation kinetics of electrical conductivity in transparent polyaniline-nylon composite films

The thermal stability of highly transparent and conducting polyaniline-Nylon 6 (PANI-N) composite films doped with various protonic acids such as hydrochloric acid(HCl), benzenesulfonic acid(BSA), sulfosalicylic acid(SSA) and ϱ-toluenesulfonic acid(TSA) was investigated at different elevated temperatures under air atmosphere. The conductivity degradation of PANI-N composite films doped with SSA and TSA was found to obey first-order reaction kinetics, while that of the other dopants was investigated to follow multiorder kinetics. Spectroscopic studies revealed that undoped composite films might be crosslinked by thermal treatment, which was reversible by protonic acid doping and alkali dedoping. From the DSC and TEM study, the crystal structure of the composite films was found to be affected by the formation of polyaniline in matrix polymer and depended on the types of the dopant species.