Mechanism of oxygen diffusion in poly(methyl methacrylate) films

The published data on the low-temperature diffusion of oxygen molecules in PMMA are analyzed in terms of the well-known dynamic structure model. Computer simulation shows that this model describes a sharp drop in the activation energy of diffusion coefficient at temperatures below 130 K. Moreover, this model allows one to explain the low rate of diffusion-controlled decay of anthracene O2 germinate pairs compared to the rate of decay proceeding with the diffusion coefficient calculated from the kinetics of oxygen addition to radicals.