Thermal and Structural Characterization of PS/ZnO Nanocomposites: Effects of ZnO Concentration on Dispersion, Thermal Stability, and Degradation Kinetics

This study investigates the thermal and structural properties of polystyrene PS/ZnO nanocomposites with varying zinc oxide (ZnO) concentrations (1, 5, and 10%) using TEM, AFM, X-ray diffraction (XRD), Raman spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermal kinetic analysis. TEM images reveal well-dispersed ZnO nanoparticles with sizes ranging from 5 to 20 nm, indicating a good compatibility between ZnO and PS. AFM analysis shows surface roughness variations with the height distribution ranging from 80 to 100 nm, aligning with the observed ZnO dispersion. XRD patterns confirm ZnO incorporation, with characteristic peaks at 31.71, 34.53, 36.26°, and others becoming more prominent with higher ZnO content. Thermal analysis reveals a clear dependence of peak temperature (T_p) on heating rate, with a notable increase in T_p from 430.5 to 457.6 °C as the heating rate increases from 20 to 30 °C/min. The Kissinger method shows activation energy values ranging from 59.16 to 55.77 kJ/mol, indicating stable thermal degradation, while the Arrhenius method yields slightly lower activation energies ranging from 37.85 to 39.84 kJ/mol, reflecting the material’s sensitivity to heating rate changes. Overall, the PS/ZnO nanocomposites exhibit enhanced thermal stability, showing potential for applications requiring high thermal resistance.