Thermal degradation and optical properties of SiC-infused polystyrene nanocomposites

The thermal degradation kinetics of polystyrene (PS) and various polystyrene-silicon carbide (PS/SiC) nanocomposite has been examined in detail and studied the reaction kinetics using non-isothermal thermogravimetry in nitrogen atmosphere at different heating rates. The activation energy of the thermal degradation was calculated using model-free methods of Kissinger-Akahira-Sunose and Tang, and the values are found to be compatible with each other. The kinetic analysis of the series of the prepared composites shows an increase in the average activation energy values with increase in the concentration of SiC nanoparticles, and the power law is found to be the best to describe the reaction model. The effect of various concentrations of SiC nanoparticles on the optical properties of the composites has been studied. The band gap energy of the nanocomposites decreases with SiC content. The SiC nanoparticles enhance the UV absorption of the composite film and modify overall optical behavior of the composite films. Further, the electronic structure and bonding properties of SiC-infused polystyrene molecule have been studied based on the DFT method by using the Gaussian09W simulation package to predict the stability and reactivity. The geometries have been analyzed using B3LYP/6-31G basis set.