Synthesis of Montmorillonite Clay/Poly(vinyl alcohol) Nanocomposites and Their Mechanical Properties

The montmorillonite/poly(vinyl alcohol) (MMT/PVA) nanocomposites films were synthesized by aqueous dispersion of MMT clay to PVA solution at 70-75 degrees C for 4 h. The average thicknesses of the MMT/PVA films were 85-120 mu m. The amount of clay was varied between 0-5 wt%. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis revealed the coexistence of exfoliated and intercalated structure of MMT clay in PVA. The Raman analysis of 1 wt% MMT/PVA showed, increased peak intensity at 1146.5 cm(-1), that is indicator of higher crystallinity compare to pure PVA. Dynamic mechanical analysis (DMA) of MMT/PVA nanocomposite films showed an increase in the storage modulus. The optimum value of storage modulus obtained was 8,752 MPa on dispersing 1.0 wt% MMT clay in the PVA yielding 20.0% increase in the storage modulus compare to the pure PVA films. Thermo-gravimetric, analysis (TGA) of the MMT/PVA nanocomposite films also showed the increase in the thermal stability with respect to pure PVA films. The 1.0 wt% MMT clay loading in PVA, improved the thermal stability of MMT/PVA to 325 degrees C compared to 250 degrees C for pure PVA.