Preparation and characterization of poly(vinyl alcohol)–clay Nanocomposite materials with amunium persulfat as an initiator

A series of polymer–clay nanocomposite (PCN) materials that consist of poly(vinyl alcohol) (PVA) and layered montmorillonite (MMT) clay are prepared by effectively dispersing the inorganic nanolayers of MMT clay in organic PVA matrix via an in situ free radical polymerization with ammonium persulphate as initiator. Ammonium persulfate cheaper and more available than organic radical initiator .Organic vinyl acetate monomers are first intercalated into the interlayer regions of organophilic clay hosts and followed by a one-step free radical polymerization. The organophilic clay is prepared by a cationic-exchange reaction between the sodium cations of MMT clay and Diallyl amin. The prepared poly(vinyl acetate)–clay (PVAc–clay) solution are then saponified via direct-hydrolysis with NaOH solution to form PVA–clay nanocomposite materials. The as-synthesized PCN materials are typically characterized by Fourier-Transformation infrared (FTIR) spectroscopy, wide-angle X-ray diffraction and transmission electron microscopy. The morphological image of as-synthesized materials is studied by scanning electron microscopy (SEM) .Effects of the material composition on the thermal stability, mechanical strength, optical clarity of PVA along with a series of PCN materials, in the form of fine powder and free-standing film, are also studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and UV–visible transmission spectra, respectively.

Keywords:

polymer-clay nanocomposite , ammonium persulfat , poly(vinyl alcohol) , montmorillonite