Abstract
The diffusion coeficient of oxygen into polymethyl methacrylate has been measured by the quenching of the phosphorescence of phenanthrene and triphenylene excited by steady-state irradiation and by flash methods. A theory is given of the relationship between the measured phosphorescence intensities and the diameter of the phosphorescent sample. An activation energy for the diffusion of oxygen has been determined and the effect of the viscosity of the medium is discussed.