Effect of stretching temperature on proton spin-lattice and spin-spin relaxation times of isotactic polypropylene film

Structural properties of isotactic polypropylene film during stretching were investigated mainly by the measurements of proton spin‐lattice, T 1 and spin‐spin, T 2 , relaxation times. Both T 1 and T 2a , T 2 of the most mobile amorphous regions, of the sample stretched at 150°C are longer than those of the sample stretched at 130°C. These results indicate that in the sample stretched at 150°C the proportion of mobile amorphous region decreases,...