Electrically Conductive Elastomer Composites Containing Polyaniline

The electrical co nductivity and mechanical properties of several elastomer-based composites containing pol yal1ilin e-dodecylbenzene sulphonic acid (PANI-DBSA) complex have been studied. An inhomogeneity of these materials (heterogeneous microdispersion of the particles of the con du ctive constituents - carbon black and PANI) was found. It was shown that structural changes took place within the hlends during storage, causing perceptible changes in the state of the conductive pathways. This non-equilibrium nature and. as a consequence, the unstable behaviour of the composites was revealed using both average conductivity and average conductivity deviation methods. A substantial decrease in the glass transition temperature (ΔTg ca. 5-15 C) of the insulating matrix polymer (styrene-butadiene rubber. nitrile-butadiene rubber or ethylenepropylene-diene terpolymer) in the composites was also found. The lowering of Tg has been attributed to the presence of OBSA (free and as counter-ions of the main PANI chains). which plasticized the polymer com posites. From an industrial point of view, the preparation of composites containing the PANI-OBSA complex is of great importance since the processability of the mixtures is facilitated.