Abstract
Solvent transport in poly(ethylene terephthalate) (PET) and related phase transformation were investigated. The data of mass sorption were analyzed according to Harmon's model for Case I (Fickian), Case II (swelling), and anomalous transport. This transport process in PET is accompanied by the induced crystallization of the original amorphous state. The transformation was examined by wide-angle X-ray scattering, small-angle X-ray scattering, differential scanning calorimetry, and Fourier transform infrared spectroscopy. During this process, the matrix is under a strain state that causes different kinetic paths of crystallization as compared with that by thermal annealing. This state of strain assists the development of the solvent-induced crystallization. The model regarding crystallization was proposed in terms of the study of long period L, the crystal thickness l c , and the thickness of amorphous layer l a obtained from the one-dimensional correlation function and interface distribution function. Different kinetic paths were discovered for different crystallization processes.