Dielectric Properties and Insulation Diagnosis of Polymers by Ultra-wideband Dielectric and Absorption Spectroscopy

本研究的目的是通过测量超宽带频段的介电常数和吸收光谱来了解聚合物薄膜的介电性能。2012财年，为了获得未来超高速宽带通信系统的有用信息，用自由空间法测量了7种聚合物在GHz频率下的介电常数。本研究的要点以参考论文的形式提交。2013财年，利用量子化学计算，对伽马射线辅助氧化产生的交联聚乙烯的吸收光谱进行了实验和数值分析。结果表明，吸收是由于光学不活跃的晶格振动通过氧化诱导的结构变化而变得活跃而引起的共振振动。此外，还探讨了用太赫兹成像检测乙丙橡胶降解的可能性。

The objective of this research is the understanding of dielectric properties of polymer films through measurements of permittivity and absorption spectra in an ultrawide-band frequency range.In FY 2012, permittivity spectra were obtained for seven kinds of polymers by the free-space method at GHz frequencies for the purpose of getting useful information on the future ultrafast wideband communication system. The essentials of this research were submitted as a refereed paper. In FY 2013, absorption spectra induced in cross-linked polyethylene by gamma-ray assisted oxidation were analyzed experimentally and numerically using quantum chemical calculations. As a result, it can be clarified that the absorption is due to resonance vibrations induced by the phenomenon that optically inactive lattice vibrations become active through oxidation-induced structural changes. In addition, possibilities of detecting the degradation of ethylene-propylene rubber by THz imaging were also examined.