Plasticizer effect and electronic diffusive behavior of polyaniline‐modified clay in polystyrene nanocomposites

Montmorillonite clay (MMT) was modified with polyaniline (Pani) and used to produce nanocomposites in a polystyrene (PS) matrix. MMT/Pani particles were evaluated by Infrared Spectroscopy (FT‐IR), where groups of both MMT and Pani were found; and by XRD, where an increase in the interlamellar distance was detected, changes on the resistive electrical behavior of MMT to a diffusive one for MMT/Pani were identified by Electrochemical Impedance Spectroscopy (EIS). Nanocomposites of PS with MMT‐Pani were produced by melt intercalation in the proportions of 1%, 3%, 5%, and 10%. They were characterized by Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), and EIS. Main results showed a decrease in the glass transition temperature and in the onset temperature according to the amount of MMT‐Pani. Analyses by EIS demonstrated a capacitive behavior (polarization) for nanocomposites containing smaller amounts of MMT‐Pani and diffusive behavior for the largest proportions, which were explained by a model of electronic diffusion in the Pani polymeric chain due to the chain intercalation observed by TEM in samples with higher concentration of MMT‐Pani. Therefore, the results suggest that the addition of MMT‐Pani alters some properties of the polystyrene matrix, changing its degradation and transition temperature, and its electrical behavior. POLYM. COMPOS., 40:37–45, 2019. © 2017 Society of Plastics Engineers