Conductive poly(2-ethyl aniline) (PEAn)/kaolinite composite was prepared by chemical polymerization in aqueous HCl medium in the presence of kaolinite particles by using potassium chromate (K(2)CrO(4)) as oxidant. Effects of polymerization conditions, such as concentrations of oxidant and 2-ethyl aniline, polymerization time and temperature on PEAn content and conductivity of composite, were investigated. The prepared composite material, having the highest PEAn content and conductivity, was obtained in the polymerization carried out at 20 degrees C for 2 h with 0.2 M K(2)CrO(4) and 0.2 M EAn. It was observed that the micro-hardness of prepared composites increased with the increase in the PEAn contents of composites. The highest micro-hardness value of 7.92 kg mm(-2) was reached at 24.6% PEAn content. Characterization of composites was carried out by FTIR spectroscopy, XRD, TGA and SEM techniques. (C) 2009 Elsevier B.V. All rights reserved.