Solid‐state relaxations in poly(ethylene oxide). II. Study using the spin‐labeling technique

Poly(ethylene oxide) (PEO) was spin‐labeled with 3‐chlorocarbonyl‐2,2,5,5‐tetramethylpyrroline‐1‐oxyl. Correlation times were calculated from 173 to 375°K. For estimating slow‐motion rotational correlation times three models were used: Brownian diffusion, “moderate jump” diffusion, and “large jump” diffusion. Analysis of the changes in the extrema separation and spectra shape with temperature strongly suggests the presence of β and γ processes in solid poly(ethylene oxide). The Brownian diffusion model gives, for the γ relaxation, an activation energy of 8 kcal mole −1 which is in good agreement with that found using dielectric relaxation measurements.