Synthesis of Clay/Poly (styrene/2-ethylhexyl acrylate) Nanocomposite Latexes via Emulsion Polymerization

In this research, nanocomposite latex based on polystyrene-co-2-ethylhexyl acrylate with layered silicate was synthesized by emulsion polymerization procedure. For increasing compatibility between the organophilic montmorillonite (Cloisite 30B) and polymer matrix, the Cloisite 30B was reacted with vinyltricholorosilane as a coupling agent to replace the edge hydroxyl groups of the layered silicate with a vinyl moiety. The chemical grafting the polymer onto surface of Cloisite 30B was clearly confirmed by FT-IR spectroscopy. Wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM) analyses were performed in order to investigate the extent of dispersion of the filler in the matrix. The glass transition temperatures of the materials were determined by differential scanning calorimetry (DSC). Also, the thermal properties of the polymer nanocomposites were characterized using (TGA) analysis. The obtained results showed that the nanocomposites with the 0.3 and 0.5 wt% nanoclay had the exfoliated structures, whereas the nanocomposite with the 1.0 wt% nanoclay had both exfoliated and intercalated structures. The formation of these structures in nanocomposite with 1.0 wt% nanoclay was confirmed by WXRD, SEM and TEM.