'Green' synthesis of silver polymer Nanocomposites of poly (2-isopropenyl-2-oxazoline-co- N-vinylpyrrolidone) and its catalytic activity

Metal-polymer nanocomposites are of great interest and mainly focused on advanced catalytic and sensor applications. Resulting from this, new copolymers composed of poly(2-isopropenyl-2-oxazoline) (PIPOx) and poly(N-vinylpyrrolidone) (PNVP) segments were prepared from highly water soluble 2-isopropenyl-2-oxazoline (IPOx) and N-vinylpyrrolidone (NVP) monomers. Finally, silver polymer nanocomposites of poly(2-isopropenyl-2-oxazoline-co-N-vinylpyrrolidone) were synthesized and reporting for the first time. All polymerizations were done in an aqueous phase with potassium persulfate as an initiator at 60 degrees C. The reaction time varied from 1 to 6 h in accordance with stoichiometric ratios of PIPOx and PNVP, leading to insoluble copolymers; which are termed as PIPOx_PNVP (75: 25), PIPOx_PNVP (50: 50), PIPOx_PNVP (25: 75) and PIPOx_PNVP (10: 90). Only, PIPOx_PNVP (10: 90) showed adequate swelling behavior in water and some other organic solvents. All the polymers were distinguished by various physicochemical spectroscopic techniques such as UV/Visible spectroscopy, Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), and FTIR analysis. Thermogravimetry (TGA) and Differential scanning calorimetry (DSC) were used to investigate thermal stability of the samples. The metalo-polymer nanocomposites (PIPOx_PNVP-SNCs) showed an apparently improved stability even when the composites were stored in air, at room temperature. The PIPOx_PNVP-SNCs showed a remarkable catalytic activity during the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride.