结构改变对聚对苯二甲酸乙二醇酯局域能级性质的影响

Structural Effects on the Properties of Localized Energy States of Poly-(Ethylene Terephthalate) Electrets

用双轴拉伸、热处理和γ射线辐照的方法制备了一系列具有不同平面取向度,不同结晶度和不同分子链长度的PET试样。通过热释电极化温度扫描法分离出对解俘获电流峰贡献的各局域能级峰。平面取向度、结晶度和γ辐照剂量的提高引起局域能级深度增加,结构缺陷种类的增多导致局域能级数增大(由二个增至六个),能级深度分布加宽。

A series of poly (ethylene terephthalate) (PET) films with different degrees of planar orientation [A(xy)z], crystallinity (Xc) and molecular weights were prepared by drawing biaxially in different stretching ratio, annealing at 110℃ for various time intervals and γ-irradiation with a large dose (0.5-4MGy) respectively. The peaks of localized energy states were separated from the detrapping current curves by means of poling temperature scanning method. It was found that the depth of localized energy levels enlarged with the rise of △(xy)z, Xc and γ-irradiation dose according to the investigations of thermally stimulated current. Due to the changes of orientation structure of molecular chain, crystalline structure and molecular chain structure, the kinds of structural defects increased, Which caused the number of localized energy states to increase from 2 to 6 and the distribution width of depth of localized levels to broaden.