Effect of matrix type and doping on polyaniline based natural rubber nanocomposites

Abstract

Conducting flexible nanocomposites were prepared based on polyaniline (doped/un-doped) and natural/nitrile rubber. These materials have a variety of applications like antistatic and anticorrosion coatings, batteries and sensors, organic electronic materials and electromagnetic wave shielding. Polyaniline (PANI) was prepared from aniline in a very simple and economical method [1]. Polyaniline is then doped using hydro bromic acid and citric acid at different molar ratios [2]. The prepared samples were characterized using Fourier Transfer Infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) to confirm the synthesis and particle size. These conducting nano particles were introduced into natural and nitrile rubber matrix using conventional method of mixing at different proportions [3]. Two different rubber matrices were selected to compare the effect of matrix type on the conductivity of resultant composites. The mechanical studies of prepared nanocomposites confirms the uniform distribution of nano powders in the matrix. As the loading of filler in composite increases, a reduction in mechanical property was observed which may be due to the agglomeration of nanoparticles during composite preparation step. Current-voltage measurements were done in Keithley 2420A source meter in voltage range of 0 to 50 Volt. Electrical conductivity of natural rubber increases 5 times on the addition of 20% of PANI, while the increase was up to 15% when doped PANI was introduced. Nitrile rubber samples show superior conductivity than natural rubber samples which may be attributed to the inherent conducting nature of nitrile rubber.