Proton spin‐lattice and spin‐spin relaxation times in annealed poly(ethylene terephthalate)

Proton spin‐lattice, T 1 , and spin‐spin, T 2 , relaxation times of poly(ethylene terephthalate) film annealed at various temperatures were measured using a broad line pulse spectrometer. The value of T 1 is closely related to the crystallinity of the sample and only one T 1 was observed for each sample, indicating that the spin diffusion is effectively operating. Even in the amorphous sample there are some nuclear spins, the motion of which is...