Structural, conformational, and polarization changes of poly(vinylidene fluoride-trifluoroethylene) copolymer induced by high-energy electron irradiation
Structural, conformational, and polarization changes of poly(vinylidene fluoride-trifluoroethylene) copolymer induced by high-energy electron irradiation
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DOI：
10.1021/ma9919561
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发表时间：
2000-05-30
期刊：
影响因子：
5.5
通讯作者：
Ramotowski, T
中科院分区：
文献类型：
--
作者：
Xu, HS;Shanthi, G;Ramotowski, T
本文用PT-IR光谱、X射线衍射和交联密度测定等方法研究了高能电子辐照聚偏氟乙烯-三氟乙烯（50/50）共聚物的结构和分子构象的变化，并与极化滞后曲线随辐照剂量的变化进行了比较。虽然在一般的照射降低宏观极性有序，这导致在室温下的共聚物中的reversible极化的最终消失，在介观结构和分子构象的变化与剂量不是单调的。在中间剂量范围内，有一个逆转的局部有序的变化与剂量，所揭示的减少的分数的TG构象的共聚物和收缩的晶格在垂直于聚合物链的方向与剂量，这可能是由于高的交联密度辐射。此外，在30 Mrad以上的剂量辐照聚合物，没有过渡行为与温度的FT-IR光谱中观察到，与早期的实验结果，铁电-顺电过渡已被消除的辐射一致。
Structural and molecular conformation changes of high-energy electron-irradiated poly-(vinylidene fluoride-trifluoroethylene) 50/50 copolymer have been investigated by means of PT-IR spectroscopy, X-ray diffraction, and cross-linking density measurement and are compared with the change of polarization hysteresis loops with dose. Although in general the irradiation reduces the macroscopic polar ordering, which leads to the eventual disappearance of the remanent polarization in the copolymer at room temperature, the change in the mesoscopic structure and molecular conformation with dose is not monotonic. In the intermediate dose range, there is a reversal of the change of local ordering with dose, as revealed by the decrease of the fraction of the TG conformation in the copolymer and contraction of the lattice in directions perpendicular to the polymer chain with dose, which could be caused by the high cross-linking density due to irradiation. In addition, for irradiated polymers at doses above 30 Mrad, no transition behavior with temperature is observed in the FT-IR spectra, consistent with the early experimental results that the ferroelectric-paraelectric transition has been eliminated by irradiation.