Electromagnetic Interference Shielding Behavior of Polyaniline/Graphite Composites Prepared by In Situ Emulsion Pathway

Polyaniline-graphite composites were prepared via in situ emulsion pathway, using different weight ratios of aniline to graphite. These composites were characterized for thermal, electrical, and spectral attributes. The thermal stability (similar to 230 degrees C) and electrical conductivity (67.9 S/cm) were improved significantly as compared with polyaniline doped with conventional inorganic dopants such as HCl (140 degrees C and 10 S/cm). Scanning electron micrographs indicated a systematic change in morphology from globular to flaky with increasing amounts of graphite. The relative shifting of UV-visible bands indicates that some interactions exist between doped polyaniline and graphite. Absorption-dominated total electromagnetic interference shielding effectiveness of the order of -33.6 dB suggests that these materials can be used as futuristic microwave shielding materials. The good electrical conductivity and thermal stability make them ideal candidates for preparing conducting composites by melt blending with conventional thermoplastics such as polyethylene, polypropylene, and polystyrene, etc. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3146-3155, 2009