Transmittance in irradiated poly(methyl methacrylate) at elevated temperatures

[[abstract]]The transient transmittance of gamma-ray irradiated poly(methyl methacrylate) at elevated temperatures is investigated. The transmittance in the ultraviolet and visible range decreases with an increase of radiation dose. We propose that the color center is responsible for the reduction of transmittance in the irradiated specimen. Then the concentration of the color center decreases with increasing annealing time at elevated temperatures. The transmittance data at 407 nm are in excellent agreement with the theoretical model in which the color center is annihilated by a second order kinetic process. The rate constant follows the Arrhenius equation. The activation energy in the range of 44.27-51.52 kJ/mol decreases with increased dose.[[fileno]]2010325010013[[department]]化學