The molecular motions of two spin nitroxide probes of vastly different geometries dissolved in poly(vinyl acetate) have been studied over a large temperature range. The smaller spherical probe's motion follows the main glass relaxation at higher temperatures and the 7 transition at lower temperatures. Its small size allows it to occupy multiple sites as indicated by the observed spectra. The larger probe appears to occupy a single type of site. Its motion follows the main relaxation at higher temperatures and appears to abruptly jump to the fl relaxation at ~330 K.
Посилання на статтю:
A paramagnetic resonance study of the molecular motions of spin probes dissolved in poly(vinyl acetate) / Jianlin Li and Edward Gelerinter* // Polymer. – 1992. – Vol 33. – P. 963-966.