Spectral characterization of morphological structure of organomodified montmorillonite clay-based epoxy nanocomposite

Abstract

Effect of organoclays on formation of intercalated/exfoliated structure in epoxy–clay nanocomposites at 2 wt% filler loading was carried by spectral analysis. Organoclays were dispersed in epoxy matrix by ultrasonication method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were carried to characterize function group, morphology of structure, surface and glass transition temperature of the nanocomposite, respectively. FTIR study reveals the presence of epoxy in the galleries of organoclays was confirmed and proves the existence of chemical bonds between the organoclays and the epoxy matrix. XRD analysis indicated that, the interlayer spacing between the clay platelets was increased significantly, thus, the polymer is able to intercalate between the clay layers. As a result, the fully exfoliated structure was found in the E + NC-III nanocomposite while the intercalated structure was obtained in the E + NC-I, E + NC-II, E + NC-IV and E + NC-V nanocomposites. The glass transition temperature measured by TGA was increased with the addition of organoclay in epoxy matrix but decreased for unmodified nanoclay and neat composite. SEM imaging showed good filler dispersion and distribution in E + NC-III nanocomposite, highlighting the very smooth surface due to absence of clay aggregates and no voids.