Abstract

• The application of bentonite to polymer industry is growing year by year. Bentonite is hydrophilic in nature and polymer is hydrophobic character. This makes the chemically incompatible. Therefore, NaCl treated bentonite as filler was used in the presence of sodium dodecyl sulphate as surfactant and pyrrole monomer to prepare polypyrrole-sodium bentonite composites by in-situ chemical oxidative polymerization method. In the preparation of polypyrrole-sodium bentonite composites (PPy-SDS-NaB), the various amounts of bentonite (4%, 8% and 12% w/v) were used. The resultant composites were designed by PPy-SDS-NaB 1, PPy-SDS-NaB 2 and PPy-SDS-NaB 3, respectively, where, PPy-SDS-NaB means polypyrrole-sodium bentonite composites in the presence of sodium dodecyl sulphate and the numbers refer to the amount of bentonite compositions. The prepared composites were characterized by FT IR, XRD, SEM and TG-DTA techniques. Their electrical properties were analyzed in the frequency range of 1 to 10 MHz by LCR measurement. From the analysis of LCR measurement, it was observed that PPy-SDS-NaB 1 has more electrical conductivity than other two composites. The optical property of the prepared composites were also analyzed in the wavelength range of 200 to 600 nm by using UV-Vis spectrophotometer and the optical band gaps were calculated by Taucs relation. From the analysis of absorption spectra, it was found that the band gaps of prepared composites are in the semiconductor wide band gap ranges of 4.0 eV to 3.8 eV and that shows great promise in sensors as well as electronic applications.