Electrical and mechanical properties of crosslinked polyanilines

Abstract Crosslinked polyanilines were prepared by three different methods, and their electrical and mechanical properties were evaluated. The first method is to crosslink between the main chains of polyaniline by heating. The second is to crosslink by forming hydrogen bond between polyanilines (being a gel state) and crystallization. The last is to crosslink at the N-position of polyanilines using isocyanate terminated 1,2-polybutadiene as a crosslinking agent. Every crosslinked polyaniline obtained form a self-standing film, and the films show increase of about ten orders of magnitude in the electric conductivity by doping and decrease in the activation energy. Especially, these tendencies are remarkable in the film prepared from the gel state (the second method). The conductivity of the film prepared from the third method is in the same level with the other films in spite of containing polybutadiene 33wt% in the film. In all films, the temperature dependence of dynamic modulus is very small. Particularly, the modulus of the film formed from the second method is less dependent on temperature in the range of −150°C to 350°C.