Abstract
The structural change of amorphous region of poly (ethylene terephthalate) (PET) films stretched uniaxially or biaxially was investigated by means of dye-diffusion behavior. The detailed stretching methods and characteristics of samples, such as crystallinity, molecular orientation and trans-gauche contents were the same as reported previously. The diffusion coefficients of disperse dye, C. I. Disperse Blue 26, were measured in the temperature range from 80°C to boiling temperature (about 100°C).
The results are summarized as follows,
(1) The morphology of amorphous region of PET inferred from the diffusivity of dye varied with stretching methods, namely orientation mode of the films.
(2) Dense network of amorphous chain showed large molecular flexibility was obtained by uniaxial stretching.
(3) On the other hand, expanded network of amorphous chain was obtained by biaxially stretching.
(4) The dye diffusion behavior of polymer film was found to be suitable for the investigation of the structure of amorphous region of polymer stretched by various methods.
