The effect of strain rate on solvent crazing of poly(ethylene terephthalate) in solutions of poly(ethylene oxide) of various molecular masses

The effect of strain rate on the behavior of PET during its tensile drawing in highly viscous liquids, such as liquid PEG (M 400) and semidilute solutions of PEO (M = (4 × 10⁴)−(1 × 10⁶)), is studied. With an increase in strain rate, the mechanism of tensile drawing of PET in PEG changes from solvent crazing to shearing; at the same time, over the selected interval of strain rates, tensile drawing of PET in semidilute solutions of PEO proceeds via the mechanism of solvent crazing. During tensile drawing of PET in PEO solutions, the behavior of PET is almost the same as the mechanism of tensile drawing in a pure solvent. This result indicates that, in the course of flow of the polymer solution through the formed porous structure, PEO is filtered off in the local tip region of the growing craze.