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Nanocomposites of poly(vinyl alcohol)(PVA),poly(vinyl pyrrolidone)(PVP) and sodium montmorillonite(Na~+MMT) were prepared by solution mixing and then cast into films.X-ray diffraction analysis and images of transmission electron microscopy establish the formation of PVA/Na~+MMT intercalated nanocomposite.Exfoliated and highly intercalated PVA/PVP/Na~+MMT nanocomposite formed in the presence of PVP.Inclusion of PVP in PVA/Na~+MMT matrix enhances the hydrogen bonding interactions between PVA and Na~+MMT and thus increases the mechanical properties and thermal stability of PVA/PVP/Na~+MMT nanocomposites compared to PVA/Na~+MMT nanocomposite.The interactions between PVA,PVP and Na~+MMT were established by the Fourier transform infrared spectroscopy.The moisture absorption tendency of both the PVA and PVA/PVP films reduced after the incorporation of Na~+MMT at 75%constant relative humidity.Differential scanning calorimetry studies show that the presence of PVP and Na~+MMT both are responsible for reducing the heat of fusion,and crystallinity of PVA.The flow behavior of the PVA,PVA/PVP and its nanocomposite solutions has been also studied.Water vapor permeability of PVA/PVP/Na~+MMT composite films decreased in the presence of nanoclay due to increasing tortuous paths for diffusion.
Nanocomposites of poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) and sodium montmorillonite (Na ~ + MMT) were prepared by solution mixing and then cast into films. X-ray diffraction analysis and images of transmission electron microscopy establish the formation of PVA / Na ~ + MMT intercalated nanocomposite. Exfoliated and highly intercalated PVA / PVP / Na ~ + MMT nanocomposite formed in the presence of PVP. Enclosure of PVP in PVA / Na ~ + MMT matrix enhances the hydrogen bonding interactions between PVA and Na ~ + MMT and then increases the mechanical properties and thermal stability of PVA / PVP / Na ~ + MMT nanocomposites compared to PVA / Na ~ + MMT nanocomposite. These interactions between PVA, PVP and Na ~ + MMT were established by the Fourier transform infrared spectroscopy. The moisture absorption tendency of both PVA and PVA / PVP films reduced after the incorporation of Na ~ + MMT at 75% constant relative humidity. Differential scanning calorimetry studies show that the presence of PVP and Na ~ + MMT both are responsib le for reducing the heat of fusion, and crystallinity of PVA. The flow behavior of the PVA, PVA / PVP and its nanocomposite solutions has been studied. Water vapor permeability of PVA / PVP / Na ~ + MMT composite films decreased in the presence of nanoclay due to increasing tortuous paths for diffusion.