抄録
The swelling kinetics of poly (ethylene terephthalate) (PET) fiber in chlorinated hydrocarbons was studied as a function of the thermal hystories of the fiber. Two types of non-Fickian anomalous diffusion behavior were exhibited, i.e. (a) Case II diffusion, and (b) the two-step diffusion in which Fickian step followed the first non-Fickian step. Fickian and Case II diffusion mechanisms were operative independently and simultaneously in the first step in most of the behavior (b). The diffusion coefficient D and the penetration velocity v were calculated using Kwei's equation. The magnitude of D obtained was in the same order as that in the swollen polymer systems.
The swelling behavior observed was discussed qualitatively in terms of the microstructure of the amorphous regions of PET fiber. It has been inferred that Fickian and Case II mechanisms are independently operative in the different parts in the amorphous regions. In addition, it has been suggested that the lateral order distribution of the amorphous regions annealed under the fixed condition is less uniform than that obtained under the relaxed condition.
