| In recent years the use of nanocomposites has become prevalent; however, the long-term stability of these materials is not well understood. In this investigation TiO2 and ZnSe nanoparticles were inserted onto a polystyrene film and exposed to UV radiation. The objective of this study was to understand and determine how the insertion nanoparticles and UV exposure would influence the thermal properties, more specifically, the physical aging of a polystyrene film. PML was used to investigate and quantify the dispersion of TiO2 and ZnSe nanoparticles on the polystyrene. FT IR was used to look into any chemical interactions. In this section of the investigation, the samples were exposed to UV radiation because of the natural occurring UV radiation that occurs in the every life. It was revealed that no chemical interactions had occurred before UV radiation. However, after UV radiation, a new peak at 1720 cm-1, that of a carbonyl group, emerged for all samples. DSC was used to investigate if such chemical interactions had any effect on its long-term stability. Results showed that the insertion of nanoparticles had actually increased the Tg, the temperature at which the polymer transition from a disordered solid to liquid. Physical aging is a phenomenon related to Tg, and is used to understand the behavior of the polymer chains. Kolraush-William-Watt's equation was used to model the polymer chains behavior using two parameters: beta, number of relaxation modes and tau, characteristic relaxation time. After physical aging investigations were completed on the samples, it was discovered that beta values for polystyrene films with increasing amounts of TiO 2 or ZnSe had decreased. It was also discovered that the values of tau had decreased for polystyrene films with increasing amounts of TiO2 or ZnSe supporting the proposition that nanoparticles would increase the long-term stability of the polystyrene film. |
