Solid State Science and Technology, Vol. 17, No 1 (2009) 12-21 ISSN 0128-7389 ELECTRICAL AND SHIELDING PROPERTIES OF CONDUCTIVE POLYMER COMPOSITE MATRIX WITH CHITOSAN Mahnaz M.Abdi a , Anuar B. Kassim a , H.N.M. Ekramul Mahmud b , Wan Mahmood Mat Yunus c , Zainal Abidin Talib c a Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia b Faculty of Chemical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia c Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia ABSTRACT The polypyrrole-chitosan (PPy-CHI) composite films formed by electrochemical polymerization were studied by electrical and mechanical techniques. The electromagnetic interference shielding effectiveness (EMI SE) at the frequencies range from 8-12 GHz was also studied. It is shown by electrical conductivity measurement and DMA (dynamic mechanical analysis) that the enhanced conductivity and mechanical properties of the prepared films are due to the presence of CHI in the composite film. Most of the composite films had more than 98% shielding of electromagnetic energy. The EMI SE shown through reflection and absorption increased with the increase in conductivity and relative shielding efficiency by reflection and absorption can be easily controlled by the electrical conductivity. INTRODUCTION Since polypyrrole can be prepared easily by electrochemical polymerization on electrodes, numerous works have been made on the characterization and finding application of this polymer in sensors, electronic and optical devices, etc. Due to high conductivity, good environmental stability and easy synthesis of polypyrrole, this conducting polymer is capable to use in EMI shielding. Some works about using this material in the Textiles are reported [1, 2]. A textile/PPy composite with EMI SE about 36 dB over a frequency range of 50 MHz–1.5 GHz was reported by M.S. Kim [3]. Shielding is the process of limiting the flow of electromagnetic fields between two locations, by separating them with a barrier made of conductive material. Transmission of electromagnetic waves may cause electromagnetic interference (EMI) as well as can be harmful to human body. EMI shielding occurs by the reflection and/or absorption of electromagnetic radiation by a material, which acts as a shield against the penetration of the radiation through it. Corresponding Author: anuar@fsas.upm.edu.my 12