Abstract
Abstract The evolution of transmittance in UV-irradiated glassy sPS at elevated temperatures was investigated. The transmission loss in UV-irradiated sPS during annealing was attributed to the generation of permanent color center. The absorbance at the wavelength of 353 nm was assumed to be proportional to the concentration of color center. A first order generation model in good agreement with the experimental data was proposed. The rate constant satisfies the Arrhenius equation, with the activation energy of color center increasing with the increase of the UV dose. A comparison of color center in UV- and gamma-irradiated sPS was discussed. Utilizing peeling-induced splitting approach, surface ripples were produced on poly (methyl methacrylate) (PMMA)-based thermoplastic polymeric thin films. The spatial wavelength of the surface structures is a linear function of the film thickness. The apparent surface residual traction and force were found to be the thickness dependence of the spatial frequency, and both the magnitudes of the apparent surface stress and force increased with the increase of the film thickness. After exposing the PMMA-based films to UV-irradiation, the effects of UV-irradiation dose were investigated on the splitting-induced surface structures. The differential ratio of the spatial wavelength to the film thickness for the UV-irradiated films is smaller than that for non-irradiated samples. Both the spatial wavelength and the apparent surface stress increased with the film thickness for the irradiated polymer films.