Determination of diffusion coefficient of oxygen into polymers by using electron spin resonance spectroscopy. II. Poly(vinyl acetate)

Electron spin resonance spectroscopy has been used to follow the kinetics of radical decay during postirradiation oxidation of poly(vinyl acetate). The oxygen uptake of γ‐irradiated spherical poly(vinyl acetate) has been determined from changes in the intensity of the ESR signal. The diffusion coefficient (D) of oxygen determined by this technique showed an inverse relation with dose. The value of the diffusion coefficient of oxygen obtained in this study, after correcting for dose and size effects is 4.5 × 10−8 cm2/s, and is in very good agreement with the literature value of D = 5.1 × 10−8 cm2/s.