作者：Wei Wang, Atsushi Taniguchi, Mototada Fukuhara, Takehiko Okada
关键字：poly(ethylene terephthalate); UV deterioration; molecular weight; mechanical properties; surface nature
论文来源：期刊
具体来源：Journal of Applied Polymer Science
发表时间：1998年

We investigated the changes in the molecular weight and also in the mechanical properties with the distance to the exposed surface of the irradiated stacked poly(ethylene terephthalate) (PET) film samples. A relation between the molecular weight and the mechanical properties of the irradiated PET was established. The relation demonstrates that the decrease in molecular weight is one of the main origins causing the deterioration in the mechanical properties. The photodegradation process developing in PET was quantitatively studied by investigating the degradation kinetics of stacked PET film samples. Our results show that the strongest degradation takes place at the exposed surface, and the degradation rate decreases with increasing the distance. This further implies that the capability to bear a tensile stress in the area near the exposed surface is much lower than that in bulk. Therefore, irradiated PET may be fractured in a lower stress. These results indicate the surface nature of ultraviolet deterioration in the physical properties of PET.