Enhancing and strengthening the mechanical properties of polystyrene nanocomposite films using ZnS-dopants for residue free packaging applications

Polystyrene (PS) nanocomposite films with different concentrations of ZnS (0, 0.1, 0.5, and 1 wt%) nanoparticles (NPs) synthesized via standard solution casting technique have been investigated to realize the boosting up their mechanical characteristics in conjunction with their structural, morphological, optical, electrical, thermal and water absorption attributes. GIXRD of the casted nanocomposite films reveal the amorphous nature and corresponding Raman peaks that match the literature works. There is no change in Raman peak position for ZnS addition, only a decrease in the intensity of the peaks, which recommends that ZnS NPs work as nanofiller in the composite films. The surface roughness of the films is increased with the increased ZnS NPs content. Furthermore, the nanocomposite films exhibit higher water and thermal stability. The residue after thermal decomposition at 6000C is reduced from 47% to zero for 1% ZnS/PS nanocomposite film. The UV-visible spectra show ultra-low transmittance in the UV region with increasing ZnS NPs content in the PS matrix, suggesting that the nanocomposites could be used as a potential UV shielding material. High-quality insulation behavior of the investigated nanocomposites is reflected through ac electrical impedance analysis. The elastic properties are strongly influenced by the ZnS NPs addition and a 20% increment in Young's modulus as the ZnS content is increased to 1%. Overall, improved ZnS/PS nanocomposite properties are suitable for fully thermally decomposed packaging applications.