Abstract: The conductivity of composite, which was prepared by in situ emulsionpolymerization technique, shows different percolation thresholds: 21. 0% for PAn/CSPEand 7. 0%for PAn/SBScomposites cast from solution. It Increases two orders of magnitude andexhibits a new percolation threshold 3. 0% for two kinds of composites after secondary dopingwith mucresol. The secondary doping noticeably increases permanent set change withpolyaniline content. The SEMimage of broken section shows that the secondary dopingchanges the ductile fracture Into the brittle fracture. The results show that the secondarydoping induced a tenuous interconnected network through expanded polyaniline backbone.Secondary doping had no marked effect on tensile strength and elongation, which Indicatesthat the tenuous Interconnected network of the conductive component had no contribution forstress-transfer. Electrochromic performance of composite film was also studied in neutral oracidic electrolyte.

Key words: Secondary doping, Polyaniline, Composite, Conductivity, Electrochromic property