Influence of copper sulphide nanoparticles on the structural, mechanical and dielectric properties of poly(vinyl alcohol)/poly(vinyl pyrrolidone) blend nanocomposites

Blend nanocomposites based on poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP) with varying content of copper sulphide (CuS) nanoparticles have been prepared by employing a green solvent casting strategy. The interaction of blend components has been assessed by using Fourier transform infrared and UV–Vis spectroscopy, scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction, thermogravimetric analysis (TGA) and differential scanning calorimetry. The spectroscopic studies have revealed the existence of strong interface interaction between the blend components as well as CuS nanoparticles. The addition of CuS nanoparticles to PVA/PVP blend has been enhancing the semi-crystalline nature of the blend. The uniform dispersion of CuS nanoparticles in the blend has been ensured by the morphology revealed through the SEM and TEM. The glass transition temperature of the composite has been found to be increasing with increase in the content of CuS revealing the ordered arrangement of nanoparticles in the blend. The excellent thermal stability of the blend nanocomposite compared to pure PVA/PVP blend and its improvement with the loading of CuS nanoparticles has been proved by TGA. The mechanical properties, electrical conductivity and dielectric behavior of the bio-degradable nanocomposites were also studied. The dielectric properties, AC and DC conductivity of the nanocomposites were significantly increased with increase in content of nanoparticles. Mechanical properties such as tensile strength and hardness of the nanocomposite have showed an increasing trend with the loading of CuS nanoparticles. The AC conductivity and dielectric properties of the blend composites have registered an increase with the loading of nanoparticles up to 10 wt% concentration.