Impact of nanoclay loading on the structural, thermal and dielectric properties of montmorillonite/polypropylene nanocomposites

Abstract

Abstract The morphological, thermal and electrical properties of nanocomposites based on polypropylene (PP) filled with 2 wt% and 6 wt% of organo‐clay montmorillonite (MMT) were studied in this research. X‐ray diffraction show an increase of the inter‐lamellar distance indicating that PP chains have been well intercalated in the galleries of the montmorillonite. Transmission electron microscopy images show a good dispersion of the nanoclay with orientation parallel to the film surface. Moreover, it is also noted that an improvement in PP/MMT nanoclay interfacial adhesion with better orientation is achieved in PP2% compared to PP6%. The study of the real, ε ′ , and imaginary, ε ″ , parts of the complex permittivity shows the presence of the α c relaxation process and an interfacial polarization only in the cases of the PP2% and PP6% nanocomposites. We note a change in the activation energy value E a (MWS) in regard to the variation of the dielectric strength parameter ∆ ε (MWS). The PP2% nanocomposite has the highest value of E a =1.027 eV, which agrees with the lowest value of ∆ ε (MWS), then decreases with PP6% to the value E a =0.962 eV. This difference reflects the highest interactions between the reinforcement (MMT nanoclay) and the matrix (PP) in the case of PP2% nanocomposite proving a good adhesion between PP matrix and MMT nanoclay and more rigid interface compared to the nanocomposite PP6%.